All these clap::Parser warnings in the layout21converters CLIs

[dan-fritchman]

It seems they really really want us to update usage of many of these Parser fields:

warning: use of deprecated unit variant `clap::ArgAction::StoreValue`: Replaced with `ArgAction::Set` or `ArgAction::Append`
  --> layout21converters/src/gds2ser.rs:18:5
   |
18 |     gds: String,
   |     ^^^
   |
   = note: `#[warn(deprecated)]` on by default

warning: use of deprecated unit variant `clap::ArgAction::StoreValue`: Replaced with `ArgAction::Set` or `ArgAction::Append`
  --> layout21converters/src/gds2ser.rs:21:5
   |
21 |     fmt: String,
   |     ^^^

warning: use of deprecated unit variant `clap::ArgAction::StoreValue`: Replaced with `ArgAction::Set` or `ArgAction::Append`
  --> layout21converters/src/gds2ser.rs:24:5
   |
24 |     out: String,
   |     ^^^

warning: use of deprecated associated function `clap::ArgMatches::is_present`: Replaced with either `ArgAction::SetTrue` or `ArgMatches::contains_id(...)`
  --> layout21converters/src/gds2ser.rs:27:14
   |
27 |     verbose: bool,
   |              ^^^^

warning: use of deprecated associated function `clap::Arg::<'help>::validator`: Replaced with `Arg::value_parser(...)`
  --> layout21converters/src/gds2ser.rs:18:5
   |
18 |     gds: String,
   |     ^^^

warning: use of deprecated associated function `clap::Arg::<'help>::validator`: Replaced with `Arg::value_parser(...)`
  --> layout21converters/src/gds2ser.rs:21:5
   |
21 |     fmt: String,
   |     ^^^

warning: use of deprecated associated function `clap::Arg::<'help>::validator`: Replaced with `Arg::value_parser(...)`
  --> layout21converters/src/gds2ser.rs:24:5
   |
24 |     out: String,
   |     ^^^

warning: function `main` is never used
  --> layout21converters/src/gds2ser.rs:30:4
   |
30 | fn main() -> Result<(), Box<dyn Error>> {
   |    ^^^^
   |
   = note: `#[warn(dead_code)]` on by default

warning: function `parse_format` is never used
  --> layout21converters/src/gds2ser.rs:37:4
   |
37 | fn parse_format(format: &str) -> Result<SerializationFormat, Box<dyn Error>> {
   |    ^^^^^^^^^^^^

   Compiling layout21converters v0.2.1 (/Users/dan/dev/Vlsir/Layout21/layout21converters)
warning: `layout21converters` (lib) generated 9 warnings
warning: use of deprecated unit variant `clap::ArgAction::StoreValue`: Replaced with `ArgAction::Set` or `ArgAction::Append`
  --> layout21converters/src/lef2yaml.rs:16:5
   |
16 |     lef: String,
   |     ^^^
   |
   = note: `#[warn(deprecated)]` on by default

warning: use of deprecated unit variant `clap::ArgAction::StoreValue`: Replaced with `ArgAction::Set` or `ArgAction::Append`
  --> layout21converters/src/lef2yaml.rs:19:5
   |
19 |     yaml: String,
   |     ^^^^

warning: use of deprecated unit variant `clap::ArgAction::StoreValue`: Replaced with `ArgAction::Set` or `ArgAction::Append`
  --> layout21converters/src/proto2gds.rs:18:5
   |
18 |     proto: String,
   |     ^^^^^
   |
   = note: `#[warn(deprecated)]` on by default

warning: use of deprecated unit variant `clap::ArgAction::StoreValue`: Replaced with `ArgAction::Set` or `ArgAction::Append`
  --> layout21converters/src/gds2proto.rs:17:5
   |
17 |     gds: String,
   |     ^^^
   |
   = note: `#[warn(deprecated)]` on by default

warning: use of deprecated unit variant `clap::ArgAction::StoreValue`: Replaced with `ArgAction::Set` or `ArgAction::Append`
  --> layout21converters/src/proto2gds.rs:20:5
   |
20 |     gds: String,
   |     ^^^

warning: use of deprecated unit variant `clap::ArgAction::StoreValue`: Replaced with `ArgAction::Set` or `ArgAction::Append`
  --> layout21converters/src/proto2gds.rs:22:5
   |
22 |     tech: String,
   |     ^^^^

warning: use of deprecated unit variant `clap::ArgAction::StoreValue`: Replaced with `ArgAction::Set` or `ArgAction::Append`
  --> layout21converters/src/gds2proto.rs:20:5
   |
20 |     proto: String,
   |     ^^^^^

warning: use of deprecated associated function `clap::ArgMatches::is_present`: Replaced with either `ArgAction::SetTrue` or `ArgMatches::contains_id(...)`
  --> layout21converters/src/lef2yaml.rs:22:14
   |
22 |     verbose: bool,
   |              ^^^^

warning: use of deprecated associated function `clap::Arg::<'help>::validator`: Replaced with `Arg::value_parser(...)`
  --> layout21converters/src/lef2yaml.rs:16:5
   |
16 |     lef: String,
   |     ^^^

warning: use of deprecated associated function `clap::Arg::<'help>::validator`: Replaced with `Arg::value_parser(...)`
  --> layout21converters/src/lef2yaml.rs:19:5
   |
19 |     yaml: String,
   |     ^^^^

warning: use of deprecated associated function `clap::ArgMatches::is_present`: Replaced with either `ArgAction::SetTrue` or `ArgMatches::contains_id(...)`
  --> layout21converters/src/proto2gds.rs:24:14
   |
24 |     verbose: bool,
   |              ^^^^

warning: use of deprecated associated function `clap::ArgMatches::is_present`: Replaced with either `ArgAction::SetTrue` or `ArgMatches::contains_id(...)`
  --> layout21converters/src/gds2proto.rs:23:14
   |
23 |     verbose: bool,
   |              ^^^^

warning: use of deprecated associated function `clap::Arg::<'help>::validator`: Replaced with `Arg::value_parser(...)`
  --> layout21converters/src/proto2gds.rs:18:5
   |
18 |     proto: String,
   |     ^^^^^

warning: use of deprecated associated function `clap::Arg::<'help>::validator`: Replaced with `Arg::value_parser(...)`
  --> layout21converters/src/proto2gds.rs:20:5
   |
20 |     gds: String,
   |     ^^^

warning: use of deprecated associated function `clap::Arg::<'help>::validator`: Replaced with `Arg::value_parser(...)`
  --> layout21converters/src/proto2gds.rs:22:5
   |
22 |     tech: String,
   |     ^^^^

warning: use of deprecated associated function `clap::Arg::<'help>::validator`: Replaced with `Arg::value_parser(...)`
  --> layout21converters/src/gds2proto.rs:17:5
   |
17 |     gds: String,
   |     ^^^

warning: use of deprecated associated function `clap::Arg::<'help>::validator`: Replaced with `Arg::value_parser(...)`
  --> layout21converters/src/gds2proto.rs:20:5
   |
20 |     proto: String,
   |     ^^^^^

warning: `layout21converters` (bin "proto2gds" test) generated 7 warnings
warning: `layout21converters` (bin "gds2ser" test) generated 7 warnings (7 duplicates)
warning: `layout21converters` (lib test) generated 8 warnings (8 duplicates)
warning: `layout21converters` (bin "gds2proto" test) generated 5 warnings
warning: `layout21converters` (bin "lef2yaml" test) generated 5 warnings

[dan-fritchman]

56e40c6 fixed this by

• Upgrading to clap ^4.0, and
• Replacing all the #[clap] decorators with #[arg]

[dan-fritchman]

Merged in via #35