A single reusable definition of get_segment_apps, etc. would be helpful

[bieryAtFnal]

There are several places in daqconf/python/daqconf that the get_segment_apps python function is defined. It would be great if a single reusable definition were provided instead.

I noticed this when working to restore the ability to specify non-standard output directories in integtests (e.g. here), and in that work, I used the definition of get_segment_apps from get_session_apps.py.

[eflumerf]

Specifically, session,py, get_session_apps.py, and enable_tpg.py, with identical functionality. This should probably be moved to utils.py