Draft workshop management

[IrynaNakoneshniuk]

Summary of Changes:

• Added Base Model TrackableBaseEntity:
  Introduced a reusable base model for non-business entities to track changes such as CreatedBy, ModifiedBy, CreatedAt, and
  ModifiedAt.
• Added WorkshopDraft and TeacherDraft introduced models to store draft data for workshops and teachers
• Added IWorkshopDraftRepository, added methods Update and Delete to ensure data consistency during concurrent access.
• Added сustom exceptions EntityDeletedConflictException and EntityModifiedConflictException
• Added Create method to IWorkshopDraftService

[sonarqubecloud]

Quality Gate failed

Failed conditions
7.1% Coverage on New Code (required ≥ 80%)

See analysis details on SonarQube Cloud