Deprecate repositories and update service interfaces

- Marked `IEnvelopeReceiverRepository` and several repository classes as obsolete, recommending the use of `IRepository`.
- Corrected `using` directive in `IReceiverService.cs`.
- Removed `UpdateAsync` method from `IReceiverService`.
- Enhanced `ISmsSender` interface with new properties and methods.
- Updated `ReceiverCreateDto`, `ReceiverReadDto`, and `UserReceiverDto` to enforce non-nullable properties.
- Refactored `TestReceiverController` to suggest using `MediatR`.

EnvelopeGenerator.Web/Controllers/Test/TestReceiverController.cs

@@ -3,13 +3,13 @@ using EnvelopeGenerator.Application.Contracts.Services;
 using EnvelopeGenerator.Application.DTOs.Receiver;
 using EnvelopeGenerator.Domain.Entities;
 
-namespace EnvelopeGenerator.Web.Controllers.Test
-{
-    public class TestReceiverController : CRUDControllerBase<IReceiverService, ReceiverCreateDto, ReceiverReadDto, ReceiverUpdateDto, Receiver, int>
-    {
-        public TestReceiverController(ILogger<TestReceiverController> logger, IReceiverService service) : base(logger, service)
-        {
+namespace EnvelopeGenerator.Web.Controllers.Test;
+
+[Obsolete("Use MediatR")]
+public class TestReceiverController : CRUDControllerBase<IReceiverService, ReceiverCreateDto, ReceiverReadDto, ReceiverUpdateDto, Receiver, int>
+{
+    public TestReceiverController(ILogger<TestReceiverController> logger, IReceiverService service) : base(logger, service)
+    {
 
-        }
     }
 }