hnb: Introduce HNB_Tests testsuite

A new Iuh CodecPort + Emulation is introduced to (de)mux RANAP and RUA
in the same SCTP socket.
The Iuh_CodecPort.ttcn file has currently a hack to be able to test
HNBAP, since titan seem to be reporting sinfo_ppid=0 when in fact it
received sinfo_ppid=20 (HNBAP).

A couple tests are added to validate HNBAP HNBRegister Request  + Accept
or Reject. In current osmo-hnodeb state, both tests pass if run
separately, but fail if run sequentially since osmo-hnodeb still doesn't
re-connect properly after first test finishes and connection is dropped.

Related: SYS#5516
Change-Id: I7227917148e98a2c777f4b05d8d2eca6e9c121b7
18 files changed