srsLTE 19.12

• Add 5G NR RRC and NGAP ASN1 packing/unpacking
• Add sync routines and broadcast channel for Sidelink
• Add cell search and MIB decoder for NB-IoT
• Add PDCP discard
• Improve RRC Reestablishment and cell measurements and procedure handling
• Add multi-carrier and MIMO support to ZMQ radio
• Refactor eNB scheduler to support multiple carriers
• Apply clang-format style on the entire code base
• Other bug-fixes and improved stability and performance in all parts