In this commit, we changed the stub function of the NRUE
to handle the MIB and SIB1, which arrive in a single
DL_TTI_REQ. If we have not received the MIB, we first
call the scheduler, then we handle any received NFAPI
messages. The NFAPI message handler will then call
the nr_ue_dl_indication() again, which will process
first the MIB, then SIB1. It seems that we are not
properly sending the SIB1 response back to the gNB so
the NRUE eventually crashes. We are however, properly
decoding the MIB and SIB which is a step in the right
direction!

In the previous commit, the NRUE would record
the time it received a slot and compare this
rx time to the next slot. If the next slot
came in before it had been 500us, the NRUE
would sleep a delta amount to make the duration
between the two slot indications 500 us. This
change complicated the code and did not
improve the performance so it was removed.
Furthermore, this commit removes the old
queueing mechanism of the slot indications and
uses calloc rather than an array.

Instead of removing the frees we allocated from heap.

See merge request aburger/openairinterface5g!78

See merge request oai/openairinterface5g!1291

MR !1277 : fixes for nr_set_pdsch_semi_static
MR !1225 : Cleanup and first step to enhance cpu measurments
MR !1278 : NR cleanup separation macphy
MR !1289 : Nr dlsch retransmission fix pucch allocation
MR !1270 : Removing hardcoded value of min channel bw for type0 pdcch
MR !1283 : Bugfix simultaneous RACH with multiple UEs

cherry-picks :
* MAC statistics in separate thread
* CI conf files update

In SA mode, there were DCI_INDs and RX_INDS that
were allocated on the stack and were assigned to
pointers used in the MAC instance. In NSA mode we
allocated these members on the heap so we free'd
them once we were done. In SA mode, they were not
allocated on the heap so this free call caused an
a free() error. We have now allocated these pointers
on the heap to avoid this error and ensure the
pointers are correct.

Added one more condition for valid cell config

See merge request aburger/openairinterface5g!75

Merge from Eurecom/develop into Eurecom/episys-merge-nsa

See merge request aburger/openairinterface5g!76