Reduces time with lock acquired.

Introduce the structure nr_pdcp_integrity_data_t and adapt code to use it.

Note: in nr_pdcp_sdu_t we keep the 'count' variable (which is also present
in nr_pdcp_integrity_data_t). They represent the same value, but 'count'
in nr_pdcp_integrity_data_t is to be specifically used for integrity while
the other one has other uses, so it's better to keep it.

We AssertFatal() if integrity fails. To be refined if needed.

The case securityModeFailure didn't seem to be implemented
properly, so I just removed it entirely.

The variable 'securityMode' did not make much sense, removed as well.
Plus for integrity, there was: securityMode |= 1 << 5 for nea1
and << 6 for nea2, which does not seem correct (I would expect << 4
and << 5 respectively), so it was properly incorrect.

'securityModeCommand->criticalExtensions.choice.securityModeCommand'
was accessed before checking that
'securityModeCommand->criticalExtensions.present'
is 'NR_SecurityModeCommand__criticalExtensions_PR_securityModeCommand',
which is wrong.

The tests 'securityMode >= NO_SECURITY_MODE' and 'securityMode != 0xff'
don't make sense/are unclear, so removed too.

So let's simplify this function, wrong in several places. And put
some AssertFatal() so that the code won't do weird things. The
AssertFatal() can be removed later and the function improved later
if needed. The case securityModeFailure can also be handled later,
but I think there is more work to do than just encoding the message
and send it to the gNB, so it's not bad to remove it for the moment.

Needed by some RRC procedures to validate the integrity of a message
before accepting it.

The use of security_mode_completed in the PDCP entity was a hack.

Plus it was not working at all with the deregistration request
when nea2 is used, sent when doing ctrl+c in the nrUE.

So let's remove it.

And let's handle activation of integrity and ciphering more in
accordance with what 38.331 says. SecurityModeComplete has to
be sent integrity protected, but not ciphered. Only after should
the ciphering be activated. (See 38.331 5.3.4.3.)

Add an API to allow out-of-order writes to a radio interface, unlike the
current interface.

this function is called in UE in this commit, even if the tx might
still be in order.

Later, i plan to improve UE pulti-threading, that will lead to out of
order tx.  also, the gNB will benefit of this new function to replace
several specific pieces of code that reorder tx with over complex and
slow systems

5G L2sim is broken since some time, and there is no time to fix it.
Remove it from the Container Parent Pipeline.

- Four mounting of files, we need the absolute path. Even if the script
  gets relative paths, realpath will give the absolute path
- Correctly recognize and handle gNB images with AW2S support

- this prevents pulling PDUs from PDCP when re-establishment is awaiting

- short and long SN sizes
- PDCP PDU header sizes
- PDCP integrity size
- getter for maximim PDCP PDU size

- no need to specify "single-ue" profile when running iperf test for 1 UE only
- default profile "balanced" can be used instead, computes BW for 1 UE correctly

- Remove IperfFromContainer
- Remove unused functions IperfExit and PingExit
- Remove unused function for iperf analysis