* trxcon: add handle_full_power_scan_req(), reduce code duplication
* trxcon: move the trxcon_fsm related stuff into its own header
* trxcon: add missing imports to trxcon.h
* trx_toolkit/data_msg.py: legacy flag is only for version 0x00
* trx_toolkit/data_msg.py: introduce header coding version 0x01
* trx_toolkit/data_msg.py: implement header version coding