Changes

tests: add trau2rtp_gen program

This test program converts TRAU-16k or TRAU-8k frames into RTP payloads,
both represented in hex.  (Hex representation of RTP payloads follows
TW-TS-005 spec; hex representation of TRAU frames is ad hoc.)  It can
be used as a basis for unit tests, verifying that a given TRAU frame
input turns into corresponding RTP output, and it can also be used
(in conjuction with additional Themyscira utilities) to turn captured
TRAU frame streams into playable audio.

Change-Id: I3cc8502406e930317b680b0ace2fce479e495ccd

tests: add unit test for HRv1 TRAU->RTP

Unit tests for TRAU->RTP conversion for FRv1 and EFR codecs were
implemented earlier, but not for HRv1.  Fill this gap in unit test
coverage.

The library code path exercised here is osmo_trau_frame_decode_8k()
followed by osmo_trau2rtp().  Both plain (RFC 5993) and extended
(TW-TS-002) RTP output formats are tested.

Change-Id: Id2703d313f52fa54465a13f3370ebb6d7d976bbd