feat(core)!: add side-chain features and constitution to UTXOs (#4134)

Description
---
Based on #4122 #4129 #4121 

- adds `SideChainFeatures` to `OutputFeatures`
- updates code and tests
- updates cucumber output feature consensus encoding
- allows MaxSizeVec to be used directly in consensus encoded structs

Motivation and Context
---
Partial implementation of RFC 312 contract constitution

How Has This Been Tested?
---
- New consensus de/encoding tests
- Manually on igor
- cucumbers pass

applications/tari_app_grpc/Cargo.toml

@@ -18,6 +18,7 @@ tari_utilities = { git = "https://github.com/tari-project/tari_utilities.git", t
 chrono = { version = "0.4.19", default-features = false }
 prost = "0.9"
 prost-types = "0.9"
+num-traits = "0.2.15"
 tonic = "0.6.2"
 
 [build-dependencies]

applications/tari_app_grpc/proto/types.proto

@@ -206,32 +206,79 @@ message TransactionOutput {
 
 // Options for UTXOs
 message OutputFeatures {
+    // Version
+    uint32 version = 1;
     // Flags are the feature flags that differentiate between outputs, eg Coinbase all of which has different rules
-    uint32 flags = 1;
+    uint32 flags = 2;
     // The maturity of the specific UTXO. This is the min lock height at which an UTXO can be spend. Coinbase UTXO
     // require a min maturity of the Coinbase_lock_height, this should be checked on receiving new blocks.
-    uint64 maturity = 2;
+    uint64 maturity = 3;
+    bytes metadata = 4;
+    // The recovery byte - not consensus critical - can help reduce the bandwidth with wallet recovery or in other
+    // instances when a wallet needs to request the complete UTXO set from a base node.
+    uint32 recovery_byte = 5;
+    SideChainFeatures sidechain_features = 6;
+    bytes unique_id = 7;
+
+    // TODO: deprecated
+    AssetOutputFeatures asset = 8;
+    bytes parent_public_key = 9;
+    MintNonFungibleFeatures mint_non_fungible = 10;
+    SideChainCheckpointFeatures sidechain_checkpoint = 11;
+    CommitteeDefinitionFeatures committee_definition = 12;
+}
 
-    bytes metadata= 3;
+message SideChainFeatures {
+    bytes contract_id = 1;
+    // ContractDefinition definition = 2;
+    ContractConstitution constitution = 3;
+}
+
+message ContractConstitution {
+    CommitteeMembers validator_committee = 1;
+    ContractAcceptanceRequirements acceptance_requirements = 2;
+    SideChainConsensus consensus = 3;
+    CheckpointParameters checkpoint_params = 4;
+    ConstitutionChangeRules constitution_change_rules = 5;
+    uint64 initial_reward = 6;
+}
 
-    AssetOutputFeatures asset = 4;
+message ContractAcceptanceRequirements {
+    uint64 acceptance_period_expiry = 1;
+    uint32 minimum_quorum_required = 2;
+}
 
-    bytes unique_id = 5;
+message CommitteeMembers {
+    repeated bytes members = 1;
+}
 
-    bytes parent_public_key = 6;
+message CheckpointParameters {
+    uint64 abandoned_interval = 1;
+    uint32 minimum_quorum_required = 2;
+}
 
-    MintNonFungibleFeatures mint_non_fungible = 7;
+message ConstitutionChangeRules {
+    uint32 change_flags = 1;
+    RequirementsForConstitutionChange requirements_for_constitution_change = 2;
+}
 
-    SideChainCheckpointFeatures sidechain_checkpoint = 8;
-    // Version
-    uint32 version = 9;
-    CommitteeDefinitionFeatures committee_definition = 10;
+message RequirementsForConstitutionChange {
+    // The minimum required constitution committee signatures required for a constitution change proposal to pass.
+    uint32 minimum_constitution_committee_signatures = 1;
+    // An allowlist of keys that are able to accept and ratify the initial constitution and its amendments. If this is
+    // None, the constitution cannot be amended.
+    CommitteeMembers constitution_committee = 2;
+}
 
-    // The recovery byte - not consensus critical - can help reduce the bandwidth with wallet recovery or in other
-    // instances when a wallet needs to request the complete UTXO set from a base node.
-    uint32 recovery_byte = 11;
+enum SideChainConsensus {
+    UNSPECIFIED = 0;
+    BFT = 1;
+    PROOF_OF_WORK = 2;
+    MERKLE_ROOT = 3;
 }
 
+// TODO: DEPRECATED
+
 message AssetOutputFeatures {
     bytes public_key = 1;
     repeated uint32 template_ids_implemented = 2;

applications/tari_app_grpc/src/conversions/mod.rs

@@ -32,6 +32,7 @@ mod new_block_template;
 mod output_features;
 mod peer;
 mod proof_of_work;
+mod sidechain_features;
 mod signature;
 mod transaction;
 mod transaction_input;

applications/tari_app_grpc/src/conversions/output_features.rs

@@ -34,6 +34,7 @@ use tari_core::transactions::transaction_components::{
     OutputFeaturesVersion,
     OutputFlags,
     SideChainCheckpointFeatures,
+    SideChainFeatures,
     TemplateParameter,
 };
 use tari_utilities::ByteArray;
@@ -54,7 +55,12 @@ impl TryFrom<grpc::OutputFeatures> for OutputFeatures {
         } else {
             Some(PublicKey::from_bytes(features.parent_public_key.as_bytes()).map_err(|err| format!("{:?}", err))?)
         };
-        let flags = u16::try_from(features.flags).map_err(|_| "Invalid output flags: overflowed u8")?;
+        let sidechain_features = features
+            .sidechain_features
+            .map(SideChainFeatures::try_from)
+            .transpose()?;
+
+        let flags = u16::try_from(features.flags).map_err(|_| "Invalid output flags: overflowed u16")?;
 
         Ok(OutputFeatures::new(
             OutputFeaturesVersion::try_from(
@@ -65,6 +71,7 @@ impl TryFrom<grpc::OutputFeatures> for OutputFeatures {
             u8::try_from(features.recovery_byte).map_err(|_| "Invalid recovery byte: overflowed u8")?,
             features.metadata,
             unique_id,
+            sidechain_features,
             parent_public_key,
             features.asset.map(|a| a.try_into()).transpose()?,
             features.mint_non_fungible.map(|m| m.try_into()).transpose()?,
@@ -77,24 +84,23 @@ impl TryFrom<grpc::OutputFeatures> for OutputFeatures {
 impl From<OutputFeatures> for grpc::OutputFeatures {
     fn from(features: OutputFeatures) -> Self {
         Self {
+            version: features.version as u32,
             flags: u32::from(features.flags.bits()),
             maturity: features.maturity,
             metadata: features.metadata,
             unique_id: features.unique_id.unwrap_or_default(),
-            parent_public_key: features
-                .parent_public_key
-                .map(|a| a.as_bytes().to_vec())
-                .unwrap_or_default(),
-            asset: features.asset.map(|a| a.into()),
-            mint_non_fungible: features.mint_non_fungible.map(|m| m.into()),
-            sidechain_checkpoint: features.sidechain_checkpoint.map(|m| m.into()),
-            version: features.version as u32,
-            committee_definition: features.committee_definition.map(|c| c.into()),
             recovery_byte: u32::from(features.recovery_byte),
+            sidechain_features: features.sidechain_features.map(Into::into),
+
+            // TODO: Deprecated
+            asset: None,
+            parent_public_key: vec![],
+            mint_non_fungible: None,
+            sidechain_checkpoint: None,
+            committee_definition: None,
         }
     }
 }
-
 impl TryFrom<grpc::AssetOutputFeatures> for AssetOutputFeatures {
     type Error = String;