drop xz package entirely

[heitbaum]

The follow changes allow the xz package to be entirely dropped

• some run testing is definitely needed
• The patches to vfs.libarchive and pvr.iptvsimple upstream able patch included (and upstreamed)
• xz still remains in the LE image as it is provided by busybox

These were the required changes:

• squashfs-tools: drop xz support
  • all images are currently zstd
• vfs.libarchive: drop support for lzma
  • upstream able patch included
• pvr.iptvsimple: drop support for lzma
  • upstream able patch included
• inputstream.ffmpegdirect: drop support for lzma
• toolchain: drop xz:host DEPEND
• linux: drop xz:host DEPEND
• Python3: drop xz:host and xz:target DEPEND
• xz: drop package

WIP:

• done:
  • full addon build test
• todo
  • Full cross (all target) builds
  • Full run tests
  • Upstream the patches to make lzma optional to Kodi binary addons