Refactor GetOrCreateCommand to GetOrCreateEndpointCommand

Renamed `GetOrCreateCommand` to `GetOrCreateEndpointCommand`
to improve clarity and consistency. Removed the old
`GetOrCreateCommand` class and handler, and introduced the
new `GetOrCreateEndpointCommand` class with equivalent
functionality.

Updated `MappingProfile` to reflect the new command name
and adjusted `CreateRecActionCommand` to use the renamed
command. Added the appropriate namespace for the new class
to ensure proper organization.

src/ReC.Application/RecActions/Commands/CreateRecActionCommand.cs

@@ -30,7 +30,7 @@ public class CreateRecActionCommandHandler(ISender sender) : IRequestHandler<Cre
         if(request.EndpointId is null)
             if(request.EndpointUri is string endpointUri)
             {
-                var endpoint = await sender.Send(new GetOrCreateCommand { Uri = endpointUri }, cancel);
+                var endpoint = await sender.Send(new GetOrCreateEndpointCommand { Uri = endpointUri }, cancel);
                 request.EndpointId = endpoint.Id;
             }
             else