fix(common, linux): Misc keyboard processor fixes for Xenial

fix(developer): crash importing blank OSK

Determine tier from `TIER.md` or environment variable `${TIER}`.

Use sed to replace any previously set tier in the watch files.

Fixes sillsdev/keyman-issues#6231.
Fixes sillsdev/keyman-issues#6125.
Fixes sillsdev/keyman-issues#5914.
Fixes sillsdev/keyman-issues#5902.
Relates to #2656.

If you attempt to import a blank OSK into the touch layout editor,
nothing happens, but behind the scenes the state was corrupted, meaning
when you attempt to continue work at some point the app will crash.

fix(developer): crash in context help

Fixes sillsdev/keyman-issues#6207.
Fixes sillsdev/keyman-issues#5801.
Fixes sillsdev/keyman-issues#5742.
Fixes sillsdev/keyman-issues#6186.
Fixes sillsdev/keyman-issues#6124.
Fixes sillsdev/keyman-issues#5647.
Fixes sillsdev/keyman-issues#5726.
Fixes sillsdev/keyman-issues#6149.
Fixes sillsdev/keyman-issues#6228.
Fixes sillsdev/keyman-issues#6001.
Fixes sillsdev/keyman-issues#6148.
Fixes sillsdev/keyman-issues#6159.
Fixes sillsdev/keyman-issues#6171.

This fixes a crash when context help is unable to determine the
current context.

fix(android): Add ability to reinitialize `CloudDownloadMgr`

* Catch specific IllegalStateException
* Replace Toast notification with `Log.e()`
* Also added a null check on the context for ResourcesUpdateTool()

change(web): Testing resources update

fix(common): Update configure-repo.sh to ln commit-msg-defs

feat(mac): install script rather than drag+drop

chore(oem): FV iconography update

feat(web): restyles prediction banner

fix(web): Fat-finger complication fixes

The installer did not work on downlevel versions
of macOS as the compile in Script Editor produced
a 10.15-compatible version. Now we build the app
directly from source with osacompile and bundle
that instead.

fix(mac): Modifier keys were resetting cached context

Per review comments

* Revert python-qrcode
* Add python3-pip to Build-Depends

Verified on Bionic

fix(ios): initial-install check within Migrations