Cleanup for server scaffolding

[markcowl]

• [ ] Validate messages
  • [ ] only print traces and ignore stderr (other than traces) unless there is an error.
  • [ ] print download location for dotnet
• [ ] Decide whether to clear all generated folders when overwrite is specified or add another option
• [ ] Check for dotnet presence in the emitter (print trace with download location and do not format)
• [ ] Debug formatting issue and update format command as appropriate
• [ ] Emit a diagnostic if use-swaggerui is chosen and no OpenAPI3 spec is available