- Delete legacy service.rs and its submodules
- Remove service module from lib.rs exports
- Clean up unused service-related code

- Remove handle, target, target_configure, target_connection modules from main library
- Create test_utils module in test project to contain temporary connection functionality
- Update import paths in test files
- Keep instance and error modules as core functionality
- Adjust vcs_test configurations to adapt to new test structure

- Add rmp-serde dependency for MessagePack serialization
- Implement write_msgpack and read_msgpack methods for basic MessagePack support
- Add write_large_msgpack and read_large_msgpack methods for chunked transmission
- Add error conversions for rmp-serde errors
- Add comprehensive tests for MessagePack functionality
- Fix code formatting and improve readability
- Make stream field pub(crate) for better access control

All tests pass successfully, ensuring backward compatibility.