Added `[Obsolete]` attributes to classes, methods, and properties related to the deprecated PSPDFKit library and notifications.
- Marked `AnnotationHandler`, `DocStatusHandler`, `AnnotationBehavior`, and `DocStatusBehavior` as obsolete.
- Marked `Handle` methods in `DocStatusHandler` and `DocStatusBehavior` as obsolete.
- Marked `PsPdfKitAnnotation` property in `SignCommand` as obsolete.
- Marked `CreateOrUpdate` method in `AnnotationController` as obsolete.
- Added `Handle` methods in `DocStatusHandler` and `DocStatusBehavior` to send `CreateDocStatusCommand`.
- Updated `AnnotationController` dependencies to include `EnvelopeGenerator.Application.Common.Dto`.
These changes indicate a transition to `Signature.Commands.SignCommand` and deprecate PSPDFKit-related functionality.