The UE had a list of known UEs. With the introduction of a separate
module for F1 UE ID handling that is also used in monolithic (to
separate CU UE ID from DU UE ID), this functionality is not needed, and
deleted in this commit.

Previously, the F1AP handler called various functions directly, instead
of sending an ITTI message to the RRC thread. This has two drawbacks:
- it can lead to data races if the RRC task uses functionality that is
  being accessed by the F1 task through this function
- no homogeneity: all other handlers send an ITTI message, so this one
  should too

- The CU/DU UE ID is used in DL RRC Message Transfer
- Note: The CU UE ID currently is still the RNTI
- on every DL RRC Message, the DU verifies that the UE exists
- Refactor RRC: common function to forward protected SRB PDUs

The RRC uses gNB_ue_ngap_id as its primary ID; the following commits
will introduce the usage of the (F1) gNB CU UE ID. This commits renames
the gNB_ue_ngap_id to rrc_ue_id to better reflect its usage as the RRC's
primary UE ID.

It will be used as the NGAP and F1 (CU) UE IDs.

To avoid 0 in the ID

for reusing the old UE Context after reestablishment: we have to free a
UE context, but that also free's the RA process that we still need.
Remove here

Is this necessary?

integration_2023_w31

See merge request oai/openairinterface5g!2282

* !1932 Introduce basic unit testing framework, cleanup
* !2259 NR_UE: improve NFAPI_NR_DMRS_TYPE1_linear_interp()
* !2271 Draft: Make asn1c debug traces functional
* !2274 remove NR UE RRC sub state
* !2278 CI: AW2S - update of AmariUE commands
* !2004 Fix gNB LLR plot view
* !2265 chore(ci): adding back LTE-UE Radio tests
* !2268 fix for PDCCH unscrambling at UE
* !2269 fixes for PUCCH F1 at UE
* !2258 pdcp_config_req_asn1 bug fix
* !2263 UE ServingCellConfigCommon cleanup
* !2275 Fix RRC UE timers based on frames and not slots
* !2280 handle scheduling of DLSCH with DCI10 in common search
* !2277 CI: no Jenkins mail, iperf refactor, add Quectel E1 test
* !2260 Preparation of release v2.0.0

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

Merge remote-tracking branch 'origin/NR_MAC_gNB_handle_DLSCH_with_DCI10_common_SS' into integration_2023_w31

- throughput test in DL
- UL throughput: 30s is enough
- increase bidir test time for more reliable measurement
- increase retx thresholds: 1% for first round is too low

The results of individual UEs (e.g., ping) is listed vertically, like
so:

| ping results | UE1 |
|              | UE2 |
|              | UE3 |

Where UE1, UE2, ... represents an entire box with results for UE 1, 2,
... For many UEs, this results in considerable need for vertical space. This
commit changes to something like the following to save space:

| ping results | UE1 UE2 UE3 |

For a single UE, this commit has no major impact (the boxes are not
stretched to width anymore).

A side effect of the previous commit's refactoring is that we mark the
pipeline as failed if a (packet loss/bitrate) threshold is violated.
Previously, the HTML would contain a "Perf not met" hint, but be marked
as successful.

This commit introduces more realistic thresholds for various pipeline
runs. The values are arbitary, following the performances in pipelines
that were marked as successful, but actually had performance problems.
They allow, though, a pipeline to pass following the normal performance
we saw the last weeks.