Merge branch 'integration_2020_wk45' into 'develop'

MR902 Nr mac ssb ro ue idcc
- Construction of SSB-RO mapping table on the UE
- RO selection based on SSB index
- RACH preamble selection based on SSB index in a selected RO
- RA-RNTI calculation
  

MR928 nr: add MAC PDU traces for wireshark
- The T tracer macpdu2wireshark has been modified to handle the new traces. The usage is the same as for LTE.  

MR929 RA fixes for NR UE  

MR938 CI: Parse UE TUN interface correctly in S1 mode
- The TUN interface configuration is changed to use program "ip" only. 
- The CI script parsing is changed accordingly: the pipeline will recognize the attempt to bring up the interface of the first UE.

MR933 nr rlc: bugfix 
- ret.next was not set in a particular case