The compiler has always been very ambiguous on which characters were
accepted in group and store names, even to the point of accepting
things like comma in a store name, which would then make it impossible
to reference in an `index` statement!
This commit clarifies the allowable characters in an identifier. While
it would have been possible to use UAX#31 for this, that would have
extended the requirements for this change substantially, and may have
caused us more trouble with legacy keyboards. Given kmcmplib is
end-of-life (see epic/ng-compiler), I have chosen a lower friction
approach. There are certainly other characters that could be excluded,
but in general I have chosen to exclude only those that will definitely
be problematic.
The set of allowable characters for deadkeys has actually been expanded
in this release to match the store and group name rules.
It is expected that there may be some impacted keyboards, but addressing
this change will be relatively straightforward, so I consider this to be
an acceptable back-compatibility trade-off, see
https://github.com/keymanapp/keyman/wiki/Principles-of-Keyman-Code-Changes#4-source-backward-compatibility-keyboard-model-and-package-source-file-formats-should-be-backward-compatibleFixes: #14604
Test-bot: skip
Build-bot: skip build:developer
