software/simpleran: general improvements

• rename ors-amarisoft to simpleran
• support external MBMSGW
• display current frequency and band
• add promise testing if frequency is out of bounds (ORS only)
• add useful information in eNB / gNB logs: host ID, FPGA version and kernel version
• keep old eNB / gNB radio logs
• support external HSS (S6), tested only for LTE