Handover support and RRC updates tracker
* [x] Change BWP enumeration scheme (1 CellId per GnbNetDevice, independent of CC/BWPs. One BwpId per BWP. !312
* [x] Change CC DL/UL EARFCN for a single BWP ARFCN (which may be used for UL, DL, or both) !314
* [x] Compute ARFCN and use it to configure PHY frequency, both via NrHelper and RRC Connection Reconfiguration !317
* [x] Fix initial cell selection, radio link failure and x2 interface setup !322
* [x] Initial handover support !192
* [x] RRC Real !374
* [x] Prioritize control allocation and account for RLC+MAC header overheads at scheduler !376
* [ ] Finish the documentation !362
* [ ] Handover between different numerologies !366
* [ ] FDD RLF testing !378
* [ ] Picocell setup !379
* [ ] FDD handover testing TBD
* [ ] Handover between BWPs TBD
* [ ] Setup beamforming TBD
* [ ] Handover metrics collection (short stay, ping-pong, interruption time) TBD
* [ ] Handover calibration scenario TBD
issue