SRS Measurements

In this Merge request was performed:

• Timing advance, wideband SNR and SNR per resource block measurements based on SRS at PHY layer of gNB;
• Fill SRS indication;
• Procedures for sending the SRS indication from PHY to MAC;
• Update the ul_prbblacklist at MAC based on SRS measurements and an ul_prbblack_SNR_threshold added in config files.

The SRS is configured at gNB with NR_SRS_Resource__nrofSRS_Ports_port1. This work will be extended to a larger number of ports in another Merge Request.