Fix multiple PDUSessions after review, now DRBs are configured sequentially, no matter what PDUSession id we receive

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

This commit fixes the implementation for removing either a single SDAP entity or all the SDAP entities of a UE.

Affected tests:
- 5G RFsim TDD do-ra
- 5g-rfsim-fdd
- 5g-rfsim
- 5grfsim-e1
- 5grfsim-24prb
- 5grfsim-fr2-32prb
- 5grfsim-fdd-phytest
- 5grfsim-u0-25prb
- 5grfsim-2x2
- 5grfsim-f1
- 5grfsim-f1-accelleran
- 4g-l2sim-tdd
- 4g-rfsim-fdd-05mhz
- 4g-rfsim-fdd-05mhz-nos1
- 4g-rfsim-fdd-10mhz
- 4g-rfsim-fdd-20mhz
- 4g-rfsim-tdd-05mhz
- 5g-l2sim

Bugfix when deleting a SDAP entity that is not the first one on the list and prevents segfault when removing the last one on the list
Fix delete entity function, a SDAP entity is a combination of a UE and PDUSession, we cannot just simply delete the first entity for a UE

integration_2023_w26

See merge request oai/openairinterface5g!2202

* !2081 Nonlinear ML receiver
* !2188 Bugfix for FR2
* !2189 Bugfix for getting band and numerology from command line for OAI UE
* !2192 Fix bugs in F1 implementation found with UBSan
* !2194 moving handling of RA success for reconfigurationWithSync at RRC
* !2031 Adding new sidelink (SL) variables
* !2148 NR MAC UE further improvements for DCI configuration
* !2164 Enable T304
* !2197 chore(ci-cn): Transition to YAML configuration scheme

Implement the #define variables required for synchronization: These
variables include offset and payload size values that vary from the Uu
interface, in relation to the PSS, SSS and PBCH elements. We also
introduce the new sl_mode command line flag, which is used to switch
between the Uu interface and SL interface. This will allow us to modify
exisitng PSS and SSS functions, without copying complete 5G functions
and only changing a few lines to support sidelink mode.

Fixing formatting for softmodem-common.h