[feature request] lz4 decoding available from Lua

[CitizenOneX]

lz4 decoding is already present on Frame, but at the time of writing doesn't seem to be available to call from Lua.

Some kinds of data that we send from the host phone to Frame will compress very efficiently with lz4 (e.g. some image icons can be compressed by 80% in my testing) meaning much faster transfer times to Frame, less memory usage on Frame if the compressed form is stored in memory - provided that decompression is fast and not too memory hungry itself (this is supposed to be something that lz4 is good at, I think.)

When sending rasterized (e.g. non-Latin) script to Frame, this is possibly even more important if it can mean the difference between being too slow for displaying realtime spoken/translated text, or keeping up.

If we could at least have (a) an lz4 decode/decompress function byte string -> byte string, that would be great; and (b) if there would be some significant benefit of minimizing memory allocations/garbage or Lua/C switching etc., if frame.display.bitmap() would benefit from allowing lz4 bytes to be directly provided, that could be an additional bit of sugar.

Thanks!