- Add E2 agent that leverages FlexRIC e2ap library
- Add documentation in openair2/E2AP/README.md
- Currently, statistics exported are random

integration_2023_w22

See merge request oai/openairinterface5g!2145

* !2036 CPPCHECK fixes for printf issues
* !2110 Improvements in CSI-RS functions
* !2132 NR fix problems found with undefined behavior sanitizer
* !2136 CI: Fix of the previous modification in iperf module (MR2100)
* !2137 chore(ci): removing OAI-Rel14-CUPS old bare-metal 4G core installation variant
* !2141 remove warning for non existing RNTI
* !2144 Build the CUUP on the cluster and minor Dockerfile fixes
* !2122 reworking MAC UE Search Space and Coreset configuration v2
* !1828 asn1c: use better version of asn1c
* !2130 ci: activate DRB ciphering and integrity protection
* !2140 F1: do not assert on unknown F1 message
* !2134 Cleanup RRC SRB data structures and make 2 PDU sessions functional

For the reestablishment, the SRB2 in the RRC reconfiguration
following the reestablishment needs to include ReestablishPDCP true.
We were not sending that. In this commit, I add a parameter to
add that parameter on demand. There might be a better solution.

Merge remote-tracking branch 'origin/NR_UE_rework_coreset_searchspace_new' into integration_2023_w22

To allow users to install asn1c quickly in install, make this directory
to allow standalone execution of install_asn1c_from_source.

The instructions are now:
sudo ls  # open sudo session, required by install_asn1c_from_source
. oaienv # read of default variables
. cmake_targets/tools/build_helper # read in functions
install_asn1c_from_source # install

CMake now takes the option ASN1C_EXEC to select an asn1c to use for
compilation. For instance, run with
cmake .. -GNinja -DASN1C_EXEC=/opt/asn1c/bin/asn1c
or
./build_oai --cmake-opt -DASN1C_EXEC=/opt/asn1c/bin/asn1c
to select the alternative asn1c. For instance, this is important for the
CI to allow to build multiple versions of OAI in parallel that might use
different commits of OAI.

Further, this patch introduces functionality to check for the support of
asn1c options that we require, and alerts the user if they are missing,
alongside a message of how to resolve the problem.

We don't work much on asn1c. The version we use has several bugs.
There is an active community out there that fixes bugs and improves
asn1c. Let's use their version.

Fix for following CPPCheck warnings
- invalidPrintfArgType
Rebased with latest develop branch w21.
Reverted modifications unrelated to printf issues.

We need to test security and integrity protection in the CI.

This commit activates ciphering+integrity protection for SRBs
and DRBs using nea2/nia2 for the amarisoft-ue + aw2s CI pipeline.

Update 'Active' flag for SRB 2 when setting it up and avoind to add it multiple times in rlc_BearerToAddModList

Signed-off-by: Raphael Defosseux <raphael.defosseux@eurecom.fr>

Previously, in f1ap_decoder.c, we asserted if we did not know a message.
Apart form decoding, we did not do anything in that file.

Additionally, in f1ap_handlers.c, we were also checking for an unknown
message, and printing a warning if a handler is not known.

This commit moves the F1AP message decoding to f1ap_handlers.c, and
deletes f1ap_decoder.c. In summary, we don't assert on an unknown
message, and compile less files. The rest is unchanged.

Signed-off-by: Raphael Defosseux <raphael.defosseux@eurecom.fr>