cli: process slave parameters after the rest of the settings are set up

cli: process slave parameters after the rest of the settings are set up

This separates setup of the master & slave type and addition of the wired
settings for "bond-slave", "bridge-slave" and "team-slave" connection types
from processing of slave type specific options.

A follow-up commit will make it possible to specify master (and slave type) for
any connection, not relying on "-slave" types.