refactor: allow default ports to be listened on by other protocols

Summary

• refactor: allow default ports to be listened on by other protocols

Previously, using a default port of another protocol would result in an error like the following

error: Invalid value "localhost:8080" for '--pg-listen <[HOST][:PORT]>': PGPROTO cannot listen on port 8080 because it is default port for HTTP

This commit allows default ports to be used by other protocols, as long as the port is not already occupied.

Close #1254 (closed)

• Cherry-pick to: none
• Docs follow-up: not necessary
• [ ] Changelog is updated