feat: use raw_value instead of arbitrary_precision

The `arbitrary_precision` feature from `serde_json` is used mostly
because of how the Cairo 0 artifact represents big numbers in raw number
format instead of string. Without this feature enabled the correct class
hash could not be obtained.

However, the implementation of this feature is problematic and has
been causing issues. Switching to `raw_value` wouldn't resolve those as
`raw_value` suffers from the very same issues as `arbitrary_precision`.
What's less bad about `raw_value` is that using it is opt-in - it
doesn't pollute number decoding like `arbitrary_precision` does. This
is important due to how Cargo resolves dependencies - dependants of this
library might be forced to enable the `serde_json` feature.

starknet-core/Cargo.toml

@@ -25,7 +25,7 @@ ethereum-types = "0.14.1"
 flate2 = "1.0.25"
 hex = "0.4.3"
 serde = { version = "1.0.160", features = ["derive"] }
-serde_json = { version = "1.0.96", features = ["arbitrary_precision"] }
+serde_json = { version = "1.0.96", features = ["raw_value"] }
 serde_with = "2.3.2"
 sha3 = "0.10.7"
 thiserror = "1.0.40"

starknet-core/src/types/contract/legacy.rs

@@ -120,7 +120,7 @@ pub struct LegacyIdentifier {
     pub destination: Option<String>,
     pub r#type: String,
     #[serde(skip_serializing_if = "Option::is_none")]
-    pub value: Option<serde_json::Number>,
+    pub value: Option<Box<serde_json::value::RawValue>>,
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
@@ -351,7 +351,7 @@ impl Serialize for RawLegacyAbiEntry {
     }
 }
 
-// We need to manually implement this because `arbitrary_precision` doesn't work with `tag`:
+// We need to manually implement this because `raw_value` doesn't work with `tag`:
 //   https://github.com/serde-rs/serde/issues/1183
 impl<'de> Deserialize<'de> for RawLegacyAbiEntry {
     fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>

starknet-core/src/types/contract/mod.rs

@@ -291,7 +291,7 @@ impl CompiledClass {
     }
 }
 
-// We need to manually implement this because `arbitrary_precision` doesn't work with `untagged`:
+// We need to manually implement this because `raw_value` doesn't work with `untagged`:
 //   https://github.com/serde-rs/serde/issues/1183
 impl<'de> Deserialize<'de> for ContractArtifact {
     fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>

starknet-providers/src/sequencer/mod.rs

@@ -760,7 +760,7 @@ impl From<RawFieldElementResponse> for Result<FieldElement, ProviderError<Gatewa
     }
 }
 
-// We need to manually implement this because `arbitrary_precision` doesn't work with `untagged`:
+// We need to manually implement this because `raw_value` doesn't work with `untagged`:
 //   https://github.com/serde-rs/serde/issues/1183
 impl<'de, T> Deserialize<'de> for GatewayResponse<T>
 where

starknet-providers/src/sequencer/models/contract.rs

@@ -44,7 +44,7 @@ pub struct CompressedLegacyContractClass {
     pub abi: Option<Vec<RawLegacyAbiEntry>>,
 }
 
-// We need to manually implement this because `arbitrary_precision` doesn't work with `untagged`:
+// We need to manually implement this because `raw_value` doesn't work with `untagged`:
 //   https://github.com/serde-rs/serde/issues/1183
 impl<'de> Deserialize<'de> for DeployedClass {
     fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>