Idea: LZ77 compress command bytes

[jkotlinski]

If further compression is needed, it would be a good win to LZ77 compress the command bytes only, as there is a lot of repetition there.
Command argument bytes should be excluded from this compression though, as they vary too much.

To keep CPU usage low, it would be best not to have such compression enabled by default.

[jkotlinski]

There are some Game Boy decompressors readily available: https://gitendo.github.io/gbcp/