Refactor receiver roles: rename FullyAuth/PreAuth for clarity

Renamed receiver roles FullyAuth → Receiver.Full and PreAuth → Receiver.TFA across the codebase for improved clarity and consistency. Updated all usages, [Authorize] attributes, role checks, authentication logic, and authorization policies to use the new role names. Marked old constants as obsolete and pointed them to the new values. This change enhances code readability and groups receiver roles under the Receiver static class.

EnvelopeGenerator.Web/Controllers/TFARegController.cs

@@ -91,7 +91,7 @@ public class TFARegController : ViewControllerBase
         }
     }
 
-    [Authorize(Roles = Role.FullyAuth)]
+    [Authorize(Roles = Role.ReceiverFull)]
     [HttpPost("auth/logout")]
     public async Task<IActionResult> LogOut()
     {