dont require stand-alone-test of frame controller
add untested frame controller design
add first working adsb receiver design

this commit introduces the first (draft) working receiver. data packets
are sent out at 115200 baud via UART and input via 8 bit UART.
also introduces new stimulus file for the receiver (containing 2
packets) and a new gtkwave-savefile. the framecontroller is working now
and implements ascii-hex coding.