smf: Initial HTTP2/SBI support

* New library/TS*_Templates.ttcn files are added providing several
  templates for SBI interface types available from
  osmo-ttcn3-openapi-generator.git.
* Split SMF_Session_CT parts which are only used during 4G tests
  (Diameter interfaces, S5/S8/S2b GTPv2C interfaces) into its own file
  SMF_Session_CT_4G. There's usually no need to look at both 4G and 5G
  specific code at the same time, since usually tests validate one or
  the other. SMF_Session_CT is left with common stuff, like lifecycle
  of component and PFCP interface.
* Add a new SMF_Session_CT_5G file containing all 5G specific logic, ie.
  HTTP2 SBI interface handling.
* Add a new test in SMF_Tests which makes use of the new
  SMF_Session_CT_5G logic to emulate a PDU Session request from a 5G UE.
  Test and infra only validates so far until UE receives the PDU session
  request after UDM/PCF validation & setup. Further work will be done in
  follow-up commits.
* Adapt open5gs config to use an SCP to route all HTTP2 traffic. This
  way we can emulate all nodes through a single HTTP2 server, and we
  emulate the SCP forwarding the messages to the proper destination.
  Hence, the NRF is disabled.

Related: SYS#7073
Change-Id: I377b748d8da6e9e53a96a85f1c730505793ecea8
---
M library/HTTP2_Functions.ttcn
A library/TS29502_Nsmf_PDUSession_Templates.ttcn
A library/TS29503_Nudm_SDM_Templates.ttcn
A library/TS29512_Npcf_SMPolicyControl_Templates.ttcn
A library/TS29518_Namf_Communication_Templates.ttcn
A library/TS29571_CommonData_Templates.ttcn
M smf/README.md
M smf/SMF_Session_CT.ttcn
A smf/SMF_Session_CT_4G.ttcn
A smf/SMF_Session_CT_5G.ttcn
M smf/SMF_Tests.ttcn
M smf/expected-results.xml
M smf/gen_links.sh
M smf/open5gs-nrf.yaml
M smf/open5gs-smf.yaml
M smf/regen_makefile.sh
M smf/testenv.cfg
17 files changed, 2,000 insertions(+), 396 deletions(-)