feat(extensions): include Substrait core extensions

[shanretoo]

Include core extensions from Subtrait.
The majority of the code originates from the un-merged pr #89.

The generated code:

// SPDX-License-Identifier: Apache-2.0
// Note that this file is auto-generated and auto-synced using `build.rs`. It is
// included in `extensions.rs`.

/// Included source of [`functions_datetime`](https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/functions_datetime.yaml).
const FUNCTIONS_DATETIME: &str = include_str!("/Users/awfover/Projects/substrait-rs/substrait/extensions/functions_datetime.yaml");

/// Included source of [`functions_comparison`](https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/functions_comparison.yaml).
const FUNCTIONS_COMPARISON: &str = include_str!("/Users/awfover/Projects/substrait-rs/substrait/extensions/functions_comparison.yaml");

/// Included source of [`functions_geometry`](https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/functions_geometry.yaml).
const FUNCTIONS_GEOMETRY: &str = include_str!("/Users/awfover/Projects/substrait-rs/substrait/extensions/functions_geometry.yaml");

/// Included source of [`functions_aggregate_approx`](https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/functions_aggregate_approx.yaml).
const FUNCTIONS_AGGREGATE_APPROX: &str = include_str!("/Users/awfover/Projects/substrait-rs/substrait/extensions/functions_aggregate_approx.yaml");

/// Included source of [`functions_logarithmic`](https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/functions_logarithmic.yaml).
const FUNCTIONS_LOGARITHMIC: &str = include_str!("/Users/awfover/Projects/substrait-rs/substrait/extensions/functions_logarithmic.yaml");

/// Included source of [`unknown`](https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/unknown.yaml).
const UNKNOWN: &str = include_str!("/Users/awfover/Projects/substrait-rs/substrait/extensions/unknown.yaml");

/// Included source of [`type_variations`](https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/type_variations.yaml).
const TYPE_VARIATIONS: &str = include_str!("/Users/awfover/Projects/substrait-rs/substrait/extensions/type_variations.yaml");

/// Included source of [`functions_string`](https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/functions_string.yaml).
const FUNCTIONS_STRING: &str = include_str!("/Users/awfover/Projects/substrait-rs/substrait/extensions/functions_string.yaml");

/// Included source of [`extension_types`](https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/extension_types.yaml).
const EXTENSION_TYPES: &str = include_str!("/Users/awfover/Projects/substrait-rs/substrait/extensions/extension_types.yaml");

/// Included source of [`functions_arithmetic`](https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/functions_arithmetic.yaml).
const FUNCTIONS_ARITHMETIC: &str = include_str!("/Users/awfover/Projects/substrait-rs/substrait/extensions/functions_arithmetic.yaml");

/// Included source of [`functions_rounding`](https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/functions_rounding.yaml).
const FUNCTIONS_ROUNDING: &str = include_str!("/Users/awfover/Projects/substrait-rs/substrait/extensions/functions_rounding.yaml");

/// Included source of [`functions_aggregate_generic`](https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/functions_aggregate_generic.yaml).
const FUNCTIONS_AGGREGATE_GENERIC: &str = include_str!("/Users/awfover/Projects/substrait-rs/substrait/extensions/functions_aggregate_generic.yaml");

/// Included source of [`functions_boolean`](https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/functions_boolean.yaml).
const FUNCTIONS_BOOLEAN: &str = include_str!("/Users/awfover/Projects/substrait-rs/substrait/extensions/functions_boolean.yaml");

/// Included source of [`functions_arithmetic_decimal`](https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/functions_arithmetic_decimal.yaml).
const FUNCTIONS_ARITHMETIC_DECIMAL: &str = include_str!("/Users/awfover/Projects/substrait-rs/substrait/extensions/functions_arithmetic_decimal.yaml");

/// Included source of [`functions_set`](https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/functions_set.yaml).
const FUNCTIONS_SET: &str = include_str!("/Users/awfover/Projects/substrait-rs/substrait/extensions/functions_set.yaml");

use std::collections::HashMap;
use std::str::FromStr;
use once_cell::sync::Lazy;
use crate::text::simple_extensions::SimpleExtensions;
use url::Url;

/// Map with Substrait core extensions. Maps URIs to included extensions.
pub static EXTENSIONS: Lazy<HashMap<Url, SimpleExtensions>> = Lazy::new(|| {
    let mut map = HashMap::new();
    map.insert(Url::from_str("https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/extension_types.yaml").expect("a valid url"), serde_yaml::from_str(EXTENSION_TYPES).expect("a valid core extension"));
    map.insert(Url::from_str("https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/functions_geometry.yaml").expect("a valid url"), serde_yaml::from_str(FUNCTIONS_GEOMETRY).expect("a valid core extension"));
    map.insert(Url::from_str("https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/functions_aggregate_approx.yaml").expect("a valid url"), serde_yaml::from_str(FUNCTIONS_AGGREGATE_APPROX).expect("a valid core extension"));
    map.insert(Url::from_str("https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/unknown.yaml").expect("a valid url"), serde_yaml::from_str(UNKNOWN).expect("a valid core extension"));
    map.insert(Url::from_str("https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/functions_boolean.yaml").expect("a valid url"), serde_yaml::from_str(FUNCTIONS_BOOLEAN).expect("a valid core extension"));
    map.insert(Url::from_str("https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/functions_logarithmic.yaml").expect("a valid url"), serde_yaml::from_str(FUNCTIONS_LOGARITHMIC).expect("a valid core extension"));
    map.insert(Url::from_str("https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/type_variations.yaml").expect("a valid url"), serde_yaml::from_str(TYPE_VARIATIONS).expect("a valid core extension"));
    map.insert(Url::from_str("https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/functions_set.yaml").expect("a valid url"), serde_yaml::from_str(FUNCTIONS_SET).expect("a valid core extension"));
    map.insert(Url::from_str("https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/functions_string.yaml").expect("a valid url"), serde_yaml::from_str(FUNCTIONS_STRING).expect("a valid core extension"));
    map.insert(Url::from_str("https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/functions_datetime.yaml").expect("a valid url"), serde_yaml::from_str(FUNCTIONS_DATETIME).expect("a valid core extension"));
    map.insert(Url::from_str("https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/functions_comparison.yaml").expect("a valid url"), serde_yaml::from_str(FUNCTIONS_COMPARISON).expect("a valid core extension"));
    map.insert(Url::from_str("https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/functions_aggregate_generic.yaml").expect("a valid url"), serde_yaml::from_str(FUNCTIONS_AGGREGATE_GENERIC).expect("a valid core extension"));
    map.insert(Url::from_str("https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/functions_arithmetic_decimal.yaml").expect("a valid url"), serde_yaml::from_str(FUNCTIONS_ARITHMETIC_DECIMAL).expect("a valid core extension"));
    map.insert(Url::from_str("https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/functions_rounding.yaml").expect("a valid url"), serde_yaml::from_str(FUNCTIONS_ROUNDING).expect("a valid core extension"));
    map.insert(Url::from_str("https://github.com/substrait-io/substrait/raw/v0.48.0/extensions/functions_arithmetic.yaml").expect("a valid url"), serde_yaml::from_str(FUNCTIONS_ARITHMETIC).expect("a valid core extension"));
    map
});

[mbrobbel]

Thanks for the PR.

I took the liberty of making some small changes to this PR:

• Use Url key and SimpleExtensions value types instead of &str
• Made extensions sources non-pub
• Use once_cell::sync::Lazy (until we get this in std: https://doc.rust-lang.org/stable/std/sync/struct.LazyLock.html)

Let me know if this makes sense to you.

[shanretoo]

Thanks for your changes.
I made a minor change to keep the generated code more human readable and updated the pr description.