Updated CreateEnvelopeCommandHandler to use IEnvelopeExecutor for managing envelope creation. Introduced CreateParmas method for parameter handling in CreateEnvelopeSQL. Corrected Dapper type mapping method name and added service registration for IEnvelopeExecutor in DependencyExtensions. Refactored SQLExecutor to enhance encapsulation. Created EnvelopeExecutor class implementing IEnvelopeExecutor for dedicated envelope operations.
- Changed `_sqlExecutor` type in `CreateEnvelopeCommandHandler` to non-generic `ISQLExecutor`.
- Updated `Handle` method to use `CreateEnvelopeAsync` for simplified parameter handling.
- Restructured `CreateEnvelopeSQL` to implement `ISQL<Envelope>` with a raw SQL command for creating envelopes.
- Added `SetDappeTypeMap<TModel>` method in `DependencyExtensions` for Dapper type mappings.
- Improved overall code structure for better separation of concerns and maintainability.
