Integration of O-RAN 7.2 FH using OSC xRAN library

• Add new 7.2 FHI library under radio/fhi_72; leverages OSC xRAN lib (fhi_lib, E release)
• Add instructions/tutorial for compilation
• Various fixes to support this library:
  • thread pool threads have maximum priority
  • new config option for enable/disable phase compensation (because we don't have 7.2 M plane, which negotiates where phase compensation happens)
  • modify default timing advance not necessary, default is fine
  • avoid memcpy of txdataF_BF if no precoding to minimize memcpys
  • load transport library load at the beginning of the RU thread, for symmetry with split 8 lib load and for 7.2 interoperability
  • Add some split 7 configuration parameters in openair0_config (split 8 interface) for 7.2 interoperability
  • maximum openair0_config number of antennas at 8
  • minor fixes for logging, asserting, fixes for stopping threads (see commit messages)

Tests:

• LiteOn FlexFi
• Benetel 650
• VVDN