nmcli: replace occurrences of master/slave with controller/port in internal code
Summary
Updates the code of nmcli to use the new terminology, and it is an internal code rework without any user-visible changes.
Purpose
Fixes #1334 (closed)
Checklist
Please read https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/blob/main/CONTRIBUTING.md before opening the merge request. In particular, check that:
-
the subject for all commits is concise and explicative -
the message for all commits explains the reason for the change -
the source is properly formatted -
any relevant documentation is up to date -
you have added unit tests if applicable