Have common implementations in one place, and expose distinct command line
argument signatures to obtain the separate tasks as separate scripts.
osmo_interact_common.py implements the parts common to all VTY and CTRL
interactions.
osmo_interact_vty.py and osmo_interact_ctrl.py implement commands I/O but only
expose command line args to directly pipe commands and responses.
osmo_verify_transcript_vty.py and osmo_verify_transcript_ctrl.py act as before,
now implemented by importing osmo_interact_{vty,ctrl}.py, only exposing the
verifification command line arguments.
Change-Id: Ie0cbd5db85ebebc893df638a07f5568632563dc9
Neels Hofmeyr