Add versioned RPC and REST migrations

[JedimEmO]

Summary

• add shared VersionMigration core trait and re-export it through RPC/REST core crates
• add opt-in versioned JSON-RPC methods and REST endpoints with typed request/response migrations
• change generated JSON-RPC server setup to trait-backed service implementations
• update generated clients, OpenRPC/OpenAPI metadata, docs, examples, and Playwright coverage

Tests

• cargo check --workspace
• cargo test -p ras-jsonrpc-macro -p ras-rest-macro --tests
• npm --prefix tests/playwright test