Changes

stp: Fix brokeness in STP_Tests_M3UA.TC_tmt_loadshare

The test was not even setting the traffic-mode in the IUT.
Furthermore, it was expecting pure round-robin behavior, which was the
older behavior of osmo-stp when loadshare traffic-mode was selected.

Actually split the test into 2, naming them properly (since round robin
is not a AS traffic mode in itself, but a possible implementation of the
loadshare traffic-mode.

The new test validates the usual loadshare traffic-mode based on SLS
distribution.

Related: SYS#7112
Depends: libosmo-sigtran.git Change-Id I61340549c596f1c04bc2269dbc165c327bf72037
Change-Id: I16d81cb2f88bb2927f248182ad4f8f27c8c24859

stp: Fix brokeness in STP_Tests_IPA.TC_tmt_loadshare

Similar to previous commit for M3UA, this time for IPA.
Since in IPA so far the SLS is fixed per ASP, we need to add an extra
sender ASP which will get a new asp_id (and hence SLS) so that we can
also test traffic being sent/distributed to the 2nd receiver.

Change-Id: I61c3efbf8e30533d051e2de506f7c8eaae7e297b

stp: STP_Tests.ttcn: Use M3UA PC and RCTX from config

Change-Id: I81c8402d5ccd6e59f2a6869927c637fff30cb952

es9p_Types_JSON: split headers into separate module

The headers used in the JSON binding of ES9+ are also used in ES2+, ES11 and ES12.
Let's split the headers into a separate module, so that we can re-use them in
other definitions too.

Change-Id: I0242c877805003fa67445800960f75ce27752383
Related: SYS#7339

RSPDefinitions_Templates: add missing default values

The template parameters of some templates lack a reasonable default.
Let's add default values to those.

Related: SYS#7339
Change-Id: Ia55d17a00462c7c7729eb0d8d24ab0556c4c6918

es9p_Types_JSON: add decoder/encoder functions for opposite direction

We currently only have ES9p encoder/decoder functions to emulate an ES9p server,
however, we will need to emulate ES9p clients too

Change-Id: Ic7e3390bd09cc9e0c91ca90ac60cdde5d2ce1384
Related: SYS#7339