Refactor repositories and enhance documentation

- Mark `IEmailTemplateRepository` and `_repository` in `ReadEmailTemplateQueryHandler` as obsolete, suggesting the use of `IRepository`.
- Update `ResetEmailTemplateCommand` with additional documentation and examples for `Type`.
- Change return type of `CreateEnvelopeReceiverCommand` to `IRequest<CreateEnvelopeReceiverResponse>`.
- Improve caching methods in `CacheExtensions.cs` for better functionality and clarity.
- Add XML documentation to the `Ok` method in `MappingExtensions`.
- Make `UserReference` property required in `ReadHistoryResponse`.

EnvelopeGenerator.Application/EnvelopeReceivers/Commands/Create/CreateEnvelopeReceiverCommand.cs

@@ -18,4 +18,4 @@ public record CreateEnvelopeReceiverCommand(
     [Required] DocumentCreateCommand Document,
     [Required] IEnumerable<ReceiverGetOrCreateCommand> Receivers,
     bool TFAEnabled = false
-    ) : CreateEnvelopeCommand(Title, Message, TFAEnabled), IRequest<CreateEnvelopeReceiverResponse?>;
+    ) : CreateEnvelopeCommand(Title, Message, TFAEnabled), IRequest<CreateEnvelopeReceiverResponse>;

EnvelopeGenerator.Application/EnvelopeReceivers/Commands/Create/CreateEnvelopeReceiverCommandHandler.cs

@@ -64,4 +64,4 @@ public class CreateEnvelopeReceiverCommandHandler : IRequestHandler<CreateEnvelo
         res.SentReceiver = _mapper.Map<IEnumerable<ReceiverReadDto>>(sentRecipients);
         return res;
     }
-}
+}