add gsup_test to catch OS#3231
Encode an Insert Subscr Data with is_ps == true to trigger the encoding bug
described in OS#3231, i.e. show that it is fixed.
Move osmo_gsup_addr_send() to a separate .c file, so that it can be overridden
in the regression test to just dump the msgb instead.
I used this test to reproduce issue OS#3231, and now that it's here we might as
well keep it, and possibly expand on it in the future.
Related: OS#3231
Change-Id: Id1453351758f3e1a9ff03bd99fefaf51886e77da
11 files changed