Previously the builder scripts defined a readonly `VERSION` environment
variable for the Keyman version. That caused problems when another
(external) script tried to define a `VERSION` variable. We encountered
this problem when trying to move the TC build steps of a configuration
into a single script (#13399) when we tried to source `~/.nvm/nvm.sh`.
This change uses a Keyman specific prefix for the version variables and
renames `VERSION` → `KEYMAN_VERSION` etc. Unfortunately these variables
are used in a lot of places, so this turned out to be a bit of a yak
shave.
Test-bot: skip
Fixes#11220.
Replaces the sed script for matching emoji in ios prepRelease with a
tiny node project that uses emoji-regex package, to reduce future
maintenance.
Also strips lingering emoji and :xxx: emoji shortcut strings from
HISTORY.md. Note that :xxx: are not stripped programatically at this
time.
