Changes

SGsAP_Emulation: Introduce proper support for server-mode

Prior to this commit, only initial (not really useful) SCTP server-mode
support existed in SGsAP_Emulation.
This is basically because MSC_Tests uses the SCTP client-mode, and
MME_Tests_SGsAP were not yet in a fully working state.

In server-mode, we have a conn_id for the listening socket and a conn_id
for the accepted socket; track them properly.
Moreover, in server node we definetly need some sort of event to wait
for the client to connect; introduce it.
Based on existing work in Iuh_Emulation.

Change-Id: Iccf4ac96c56e947529f0ffc06428e2325a115d50

mme: Initial working state for MME_Tests_SGsAP.ttcn tests

MME_Tests_SGsAP.ttcn tests were introduced to the repository many years
ago (~2019), but they were mostly WIP and were never run as part of the
regular testsuite.

This commit reworks and extends previous work to get them up to date
with current MME_Tests and makes most of them passing.

TC_sgsap_alert_* tests are still in WIP and will be fixed in follow-up
work.

Related: OS#6850
Change-Id: If07f1a67eb4213985da82afec94adb08786a0980

mme: Store and check {mme,enb}_ue_id over S1AP

* Generate a different enb_ue_id based on imsi_suffix, and store it
  during startup of ConnHdlr.
* Validate the MME sends the expected message to the expected enb_ue_id.
* Store the mme_ue_id and validate also that MME keeps using it.

A new procedure is added to S1AP_Emulation, similar to what already
exists in NGAP_Emulation, to obtain the mme_ue_id allocated by the peer.
This is needed because upon rx of DL NAS Transport messages we only
receive the upper layer NAS decoded in the Connhdlr, so we can't store
and track the MME ID early enough.

Change-Id: I62902db3851f48ce9f80cb1cc84797735c0091de

mme: Introduce test TC_s1ap_tau_periodic

Change-Id: I261c3421f6a082e0d610ece4cc96d3e031022891

mme: Fix implementation of TC_sgsap_alert*

Change-Id: I717c6f153ae77874170bf03e7a6c7bb628d12dba

*/osmo-*.cfg: make stderr logging consistent

Use the following options for stderr logging in all config, to make the
output consistent and readable (e.g. no hex categories, no long paths to
source files at the end of log lines). Use the same order of parameters
in all files.

  log stderr
   logging filter all 1
   logging color 1
   logging timestamp 1
   logging print extended-timestamp 1
   logging print file basename last
   logging print category 1
   logging print category-hex 0
   logging print level 1

Related: OS#6272
Change-Id: I229cce244719b3ce61afb6df33fe0ca20dc22456

es2p_Types_JSON: add ES2p JSON encoder/decoder

This patch adds ES2p encoder/decoder functions.

Change-Id: Ic6e230bdd0b2c43a5183cd1f53b930e6f3c53e66
Related: SYS#7339

es12_Types_JSON: add ES12 JSON encoder/decoder

This patch adds ES12 encoder/decoder functions.

Related: SYS#7339
Change-Id: I875cbb3a6dab6ac1eac5df1199f6fb71738a744e