CBRA Procedure Working for SA Mode

See merge request aburger/openairinterface5g!81

Merge remote-tracking branch 'origin/episys/mel/sa_development_init' into episys/david/nsa_ci_debug_for_sa

Got rid of unnecessary mac->scc check as well

The following was changed in this commit:
 - A new struct in the mac instance was created
   for all emulated L1 fields.
 - NR UE RRC state bug was fixed
 - Checking the RAR rnti based on the MAC instance
   ra.ra_rnti and not hardcoding to 0x10b
 - Modified the name of the new emulate_l2 flag
   to make sense: emulate_l1

The DCIs are filtered already in the NRUE when
the NFAPI messages are handled.

Also, changed some if statement formatting.

In SA mode, we will not be able to process the SIB if
we change for mac->scc_SIB == NULL : return;

So we change the statement for NSA mode

It will likely break SA mode because it will
filter out Msg3. I will come back to this and
fix it for Msg3.

Also, reverted a DCI filtering change to exist again.

Need to review this with Raymond.

Resolved conflict in Merge remote-tracking branch 'origin/episys/master-nsa' into episys/david/nsa_ci_debug_for_sa

For multiple UEs, we need to be able to filter the rx'd messages by
the RNTI. However, we do not have the RNTI value until the CFRA (NSA)
or CBRA (SA) procedure is complete. The check below will handle this.
Also, depending on the RNTI value, we can have a SIB (0xffff), RAR (0x10b),
Msg3 (TC_RNTI) or an actual DCI message (CRNTI). When we get Msg3, the
MAC instance of the UE still has a CRNTI = 0. Only once the RA procedure
succeeds is the CRNTI value updated to the TC_RNTI.