parameters during `on_proc_begin`

- Fix let_underscore_future warning by properly awaiting async functions
- Make accept_import function async to match add_mapping usage
- Propagate errors properly with ? operator instead of ignoring them
- Replace manual Default implementation with derive attribute
- Replace vec! with array literal to avoid useless_vec warning
- All tests pass and code is now Clippy clean

- Add async callback support with proper argument passing
- Implement remote action invocation via TCP connection
- Add hello_world_action example demonstrating async communication
- Improve ActionPool with type-safe async processing
- Update client registry for remote action handling
- Enhance ActionContext with better instance management
- Support both local and remote action execution modes

- Add process_json method to ActionPool for type-agnostic calls using JSON serialization
- Extend ActionContext with action_name and action_args fields and setter methods
- Update action_gen macro to use process_json instead of typed process method
- Implement remote action invocation framework in client_registry and action_service
- Add protocol definitions for remote action communication
- Enable flexible action execution without explicit type specifications

- Extend action_gen macro to generate JSON serialization logic
- Implement generic action processing using JSON text for type-agnostic calls
- Add callback mechanism with action name and arguments in ActionPool
- Update client and server registries to use new callback system
- Improve action system flexibility at the cost of serialization overhead