New protocol decoder: xy2-100

libsigrokdecode now supports yet another protocol decoder: xy2-100.

This is a protocol used to communicate with laser scanner galvanometers, used for laser shows, laser engravers and similar applications.

Some example traces are available in the sigrok-dumps repo but we'd love to have some where we can verify proper operation of the enhanced mode (i.e. where command/parameter pairs are sent). The status/feedback signal also has only pretty basic decoding for now, so if you have dumps where the status/feedback signal is included, please let us know!

The decoder was initially written by Uli Huber, thanks a lot!