Yosys $fsm cell JSON: decoding STATE_TABLE and TRANS_TABLE

After fsm_detect and fsm_extract, write_json stores each $fsm cell's parameters as MSB-first binary strings. In STATE_TABLE, state i is the i-th STATE_BITS-wide chunk counted from the right. Each TRANS_TABLE entry is also counted from the right and laid out MSB-first as: state_in index, ctrl_in cube (0/1/- per bit), state_out index, ctrl_out. CTRL_IN connection bits in the JSON are LSB-first, so reverse them to line them up with the cube. To force detection on a register Yosys skips, run opt -nodffe -nosdff, then setattr -set fsm_encoding "auto" w:<sig>.