TODO: new compression formats

[davidnewhall]

Add support for these where possible and reasonable:

• lz4 .lz4
• brotli .br
• snappy .sz
• xz .xz
• zlib .zz
• compress/lzw .Z
• zstandard .zst
• lzh .lzh, .lha (not ready)
• lzx .lzx (three parts, needs a detector?)
• ar .deb
• rpm .rpm
• cpio .cpio
• asar .asar
• cab .cab
• lzma .lzma .lz .lzip
• arj arj (requested but no library exists)

Include additional extensions we may be missing, especially for the variants of compression+tar.

[davidnewhall]

(this all needs testing, and I've just been busy)

[akshaybabloo]

xz tested and works good