fix: handle unparsed canboatjs buffers

[tkurki]

Convert Buffers to hex

[cmotelet]

It is not the chunk that is a Buffer but only the data key.
chunk dump:
pgn: { canId: 435750147, prio: 6, src: 3, dst: 255, pgn: 129285, timestamp: '2024-01-14T19:40:53.823Z' }, length: 8, data: <Buffer 04 bd f1 46 17 66 7d 73> }