Rename method in SignatureController to Get

Renamed the method `GetAnnotsOfReceiver` to `Get` in the
`SignatureController` class. This change simplifies the method
name, making it more generic and potentially aligning with
naming conventions or broader use cases.

EnvelopeGenerator.API/Controllers/SignatureController.cs

@@ -36,7 +36,7 @@ public class SignatureController : ControllerBase
     /// <returns></returns>
     [Authorize(Policy = AuthPolicy.Receiver)]
     [HttpGet("{envelopeKey}")]
-    public async Task<IActionResult> GetAnnotsOfReceiver(string envelopeKey, CancellationToken cancel)
+    public async Task<IActionResult> Get(string envelopeKey, CancellationToken cancel)
     {
         int envelopeId = User.EnvelopeId();