[rpc] Prestate and statediff tracers

[dhil]

No description provided.

[Copilot]

Pull Request Overview

This PR adds support for prestate and statediff tracers to the RPC layer, extending the existing call tracer functionality. The implementation introduces a new MonadTracer enum to handle different tracer types and updates the tracing infrastructure to support both prestate and statediff modes.

• Introduces MonadTracer enum with support for NoopTracer, CallTracer, PreStateTracer, and StateDiffTracer
• Updates the tracing configuration to include diff_mode and only_top_call options
• Adds CBOR decoding support for prestate and statediff tracer outputs

Reviewed Changes

Copilot reviewed 7 out of 8 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
monad-ethcall/src/lib.rs	Introduces MonadTracer enum and updates eth_call function to use tracer enum instead of boolean
monad-rpc/src/handlers/eth/call.rs	Updates call handling to support new tracer types and adds CBOR decoding for prestate/statediff outputs
monad-rpc/src/handlers/eth/gas.rs	Updates gas estimation to use MonadTracer::NoopTracer instead of boolean false
monad-rpc/src/handlers/debug.rs	Expands TracerObject to include TracerConfig with diff_mode and only_top_call options
monad-rpc/Cargo.toml	Adds serde_cbor dependency for CBOR deserialization
Cargo.toml	Adds serde_cbor workspace dependency
monad-cxx/monad-execution	Updates submodule commit to support new tracer functionality

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[philipglazman]

Returning BoxRawValue will break rpc documentation since we use the return type to generate user-facing docs and the return type will be ambigious.

[andr-dev]

I think this is fine for now since debug_traceCall might return one of many types which do not yet exist in rust. They are CBOR serialized which we deserialize into a generic "Value" (like serde_json::Value) which then gets JSON serialized and returned.