library/Misc_Helpers: add f_osmo_repo_is()

Create functions to check which from Osmocom repository the SUT is
running. Put it in Misc_Helpers instead of a new library file since
Misc_Helpers is already available in many/all? tests and it fits there
too.

Depends: docker-playground Ic06532f7a67e59458652c5cf4c8f6fee8113e703
Related: OS#5327
Change-Id: Ic33d08992ea84af006d133db6aec508a7b7c7f28
1 file changed