Deprecate user service interfaces in controllers

Added [Obsolete] attributes to _userService in AuthController,
_repository in EmailTemplateController, and _userRepository
in EnvelopeExecutor. These changes guide developers to
transition to using MediatR and IRepository.

EnvelopeGenerator.GeneratorAPI/Controllers/AuthController.cs

@@ -16,6 +16,7 @@ namespace EnvelopeGenerator.GeneratorAPI.Controllers;
 public partial class AuthController : ControllerBase
 {
     private readonly ILogger<AuthController> _logger;
+    [Obsolete("Use MediatR")]
     private readonly IUserService _userService;
     private readonly IDirectorySearchService _dirSearchService;
 
@@ -25,6 +26,7 @@ public partial class AuthController : ControllerBase
     /// <param name="logger">The logger instance.</param>
     /// <param name="userService">The user service instance.</param>
     /// <param name="dirSearchService">The directory search service instance.</param>
+    [Obsolete("Use MediatR")]
     public AuthController(ILogger<AuthController> logger, IUserService userService, IDirectorySearchService dirSearchService)
     {
         _logger = logger;

EnvelopeGenerator.GeneratorAPI/Controllers/EmailTemplateController.cs

@@ -27,6 +27,7 @@ public class EmailTemplateController : ControllerBase
 
     private readonly IMapper _mapper;
 
+    [Obsolete("Use IRepository")]
     private readonly IEmailTemplateRepository _repository;
 
     private readonly IMediator _mediator;
@@ -38,6 +39,7 @@ public class EmailTemplateController : ControllerBase
     /// <param name="repository">
     /// Die AutoMapper-Instanz, die zum Zuordnen von Objekten verwendet wird.
     /// </param>
+    [Obsolete("Use IRepository")]
     public EmailTemplateController(IMapper mapper, IEmailTemplateRepository repository, ILogger<EmailTemplateController> logger, IMediator mediator)
     {
         _mapper = mapper;
@@ -115,4 +117,4 @@ public class EmailTemplateController : ControllerBase
             return Ok();
         }
     }
-}
+}