[ios] UI LM Management

[ios] Add keyboard from Language Settings

[ios] test target and swift reachability

Merge pull request #1871 from keymanapp/developer-lexical-model-compiler-include-fix-1861-regression

[Developer] Include index.ts in tsconfig.json for Lexical Model compiler

[web] [iOS] [Android] Adjust position of subkeys and key previews

[ios] Update installing a multilingual keyboard from local kmp package

Language Settings can now add a new keyboard via LanguageSpecificViewController, a subclass of LanguageViewController
LanguageViewController made more easily subclassable so languages variable doesn't have to be exposed

[Developer] Remove Object.values() in favour of Object.keys().

begins work on keeping better track of languages and related data

[Mac] fix out-of-date context buffer after keyboard commands

[Mac] fix two deadkey issues

[Mac] add support for if(), set(), reset(), save()

[Developer] Add testing infrastructure for JS code.

[Web] Predict vs correct options

[Android] Predict vs correct options