Add support for CANFD frames

[weinshec]

CAN-FD frames have a different syntax in .asc files, e.g.

7.387573 CANFD 1 Rx 12b80210x   1 0 a 16 e4 67 48 4c 4b 1a 91 07 66 65 a9 c1 c2 5b bf 8f 0 0 3200 0 0 0 0 0
7.387918 CANFD 1 Rx 12b80610x   1 0 8 8 66 6f 7f 65 0e fd 58 3f 0 0 3200 0 0 0 0 0
7.392600 CANFD 1 Rx 6e   1 0 6 6 ec 0a 22 ff ff f1 0 0 3000 0 0 0 0 0

as opposed to normal CAN syntax e.g.

0.962604 3 368 Rx d 4 cc 55 01 00 Length = 0 BitCount = 0 ID = 872