clean up
merge recovery-cm changes to bootloader message:

- merge "Do not wipe block misc on bootloader msg update"
- merge "Allow custom bootloader msg offset in block misc"
- merge "updater: Use custom bootloader msg offset for stage functions"
- merge "updater: Fix multi-stage docs and code"
always build updater binary along recovery
merge: TWRP screen capture function

Many thanks to @Tasssadar for bringing up this:
https://github.com/omnirom/android_bootable_recovery/commit/03fd6c56fe57dcd7cc4a7f7166a00ece42491558

We will drop fb2png use in next commits
drop fb2png binary support
clean up code
enable screen capture through adb shell

this restores fb2png as a built in library
fb2png is now a recovery symlink: this spares +100Kb
fb2png library is only used for adb shell screen capture
touch shortcut uses the new inline code from previous commits
6.56.0