Generated affixes

[oliveryasuna]

It would be useful is there was an option to add prefixes and suffixes to generated messages.

I am using protobufs as the encoding for bodies in HTTP requests/responses (no gRPC). So, in a way, the generated types represent DTOs. It would be useful if I could have the generator append Dto to make that clear in code.

[stephenh]

Hi @oliveryasuna , that seems like a simple addition; if you'd like to work on a PR, that'd be great. Thanks!