Removed unused function and implemented scrubbing perriod counter...
Removed unused function and implemented scrubbing perriod counter
- removed send_dumb_hk function since it is useless
- added a new CMake build option 'FSW_Instrument_Scrubbing' to count scrubbing
cycles and deduce scrubbing period. When enabled, this will steal the
lfr_fpga_version[BYTE_0] field from houskeeping packets.