Introduce new extension methods in `ControllerExtensions` to safely extract user information from a `ClaimsPrincipal`. Updated methods for ID, username, surname, given name, and email to return `null` if not found, enhancing flexibility. Updated `EnvelopeReceiverController` to utilize these new methods for improved handling of absent user claims.
- Updated `ISQLExecutor<TEntity>` to inherit from new `ISQLExecutor` interface for improved SQL execution flexibility.
- Added package references for `Dapper` and `DigitalData.Core` in project files.
- Modified `CreateEnvelopeCommand` to include `[BindNever]` on `UserId` for better model binding control.
- Refactored `CreateEnvelopeCommandHandler` to use `DynamicParameters` for SQL parameter handling.
- Updated `CreateEnvelopeSQL` to select only the top record for performance.
- Introduced `GetIdOrDefault` method in `ControllerExtensions` for user ID retrieval with fallback.
- Added `CreateAsync` method in `EnvelopeController` for envelope creation using `IMediator`.
- Ensured infrastructure project has necessary package references.
- Refactored `SQLExecutor` to implement new interface and simplified constructor.
- Introduced `SQLExecutorBaseEntity` for entity-specific SQL command execution.
- Refactoring der Erweiterungsmethoden, sodass sie auf `ClaimsPrincipal` anstatt auf `ControllerBase` basieren.
- Alle Verweise und Verwendungen dieser Erweiterungsmethoden im gesamten Code aktualisiert.
- Dies verbessert die Flexibilität und entkoppelt das Abrufen von Benutzeransprüchen von den Controllern.
