Improvements in handling the beamforming procedure via FAPI

This MR follows !2784 (merged) in the framework to develop procedure for analog beamforming (and distributed antenna systems). Here the SCF FAPI digital beamforming messages are exploited also for analog beamforming and they can be set via configuration file. The old and unused field for beamforming weights in the RU has been removed. L1 and L2 procedures have been adapted to properly handle the possibility of concurrent beams (multiple beams used simultaneously).

The work is not completed. The RU part is still mostly missing and there are still improvements required at L2.