* feat: implement draft functionality with apply and discard methods, and add benchmarks and tests
* Refactor Draft management and integrate Tokio for asynchronous operations
- Introduced a new `IVerge` struct for configuration management.
- Updated `Draft` struct to use `Arc<RwLock>` for better concurrency handling.
- Added asynchronous editing capabilities to `Draft` using Tokio.
- Replaced synchronous editing methods with asynchronous counterparts.
- Updated benchmark tests to reflect changes in the `Draft` API.
- Removed redundant draft utility module and integrated its functionality into the main `Draft` implementation.
- Adjusted tests to validate new behavior and ensure correctness of the `Draft` management flow.
