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/EmailTemplates/Queries/Read/ReadEmailTemplateQueryHandler.cs

@@ -12,6 +12,7 @@ public class ReadEmailTemplateQueryHandler : IRequestHandler<ReadEmailTemplateQu
 {
     private readonly IMapper _mapper;
 
+    [Obsolete("Use Read-method returning IReadQuery<TEntity> instead.")]
     private readonly IEmailTemplateRepository _repository;
 
     /// <summary>
@@ -21,6 +22,7 @@ public class ReadEmailTemplateQueryHandler : IRequestHandler<ReadEmailTemplateQu
     /// <param name="repository">
     /// Die AutoMapper-Instanz, die zum Zuordnen von Objekten verwendet wird.
     /// </param>
+    [Obsolete("Use Read-method returning IReadQuery<TEntity> instead.")]
     public ReadEmailTemplateQueryHandler(IMapper mapper, IEmailTemplateRepository repository)
     {
         _mapper = mapper;
@@ -34,6 +36,7 @@ public class ReadEmailTemplateQueryHandler : IRequestHandler<ReadEmailTemplateQu
     /// <param name="cancellationToken"></param>
     /// <returns></returns>
     /// <exception cref="InvalidOperationException"></exception>
+    [Obsolete("Use IRepository")]
     public async Task<ReadEmailTemplateResponse?> Handle(ReadEmailTemplateQuery request, CancellationToken cancellationToken)
     {
         var temp = request.Id is int id
@@ -46,4 +49,4 @@ public class ReadEmailTemplateQueryHandler : IRequestHandler<ReadEmailTemplateQu
 
         return res;
     }
-}
+}