feature: client port fowarding should be done by port name instead of port number

## Overview
If the port forwarding is done via port names, will become easier to host arbitry ports as well from local and remote.

Start by locating the client port-forwarding entry point and reading how it currently selects ports by number. Define the expected behavior for selecting ports by name and for arbitrary local and remote ports. Done means the client forwards named ports reliably in both local and remote cases, with tests covering the new behavior.

Written by the indexing model from the issue text.