Deprecate methods and streamline controller code

Added [Obsolete("Use MediatR")] attribute to several methods
across `DocumentController`, `HomeController`,
`TestConfigController`, `TestDocumentReceiverElementController`,
and `TestEnvelopeController` to indicate they should no longer
be used.

Refactored constructors in `TestConfigController` and
`TestEnvelopeController` to remove unnecessary empty blocks.

Improved formatting and structure of the `GetAll` method in
`TestEnvelopeController` for better clarity while maintaining
functionality.

Updated `Program.cs` to suppress warnings about obsolete
types/members during service registrations, indicating a
transition to newer implementations.

EnvelopeGenerator.Web/Controllers/HomeController.cs

@@ -171,6 +171,7 @@ public class HomeController : ViewControllerBase
         }
     }
 
+    [Obsolete("Use MediatR")]
     private async Task<IActionResult> CreateShowEnvelopeView(string envelopeReceiverId, EnvelopeReceiverDto er)
     {
         try
@@ -259,6 +260,7 @@ public class HomeController : ViewControllerBase
         }
     }
 
+    [Obsolete("Use MediatR")]
     [NonAction]
     private async Task<IActionResult?> HandleAccessCodeAsync(Auth auth, EnvelopeReceiverSecretDto er_secret, string envelopeReceiverId)
     {
@@ -331,6 +333,7 @@ public class HomeController : ViewControllerBase
     #endregion
 
     [HttpPost("EnvelopeKey/{envelopeReceiverId}/Locked")]
+    [Obsolete("Use MediatR")]
     public async Task<IActionResult> LogInEnvelope([FromRoute] string envelopeReceiverId, [FromForm] Auth auth)
     {
         try