Consolidate test frameworks and cleanup, including:
* all tests use Google Test
* reorganize folders, esp. kmnkbd -> api
* move all api tests into api folder
* replace references to test_assert or test_color with gtest equivalents
* leverage gtest patterns to remove boilerplate code
* dramatically simplify meson.build files and localize variables
* move shared helper code into helpers/ folder
* make test names unique and add gtest protocol for reporting back to
teamcity
Fixes:
* CLDR test keyboards had invalid unicodeset escapes (needs to be raised
upstream also) - was not failing tests because files were not loading
but returning success
Test-bot: skip
When normalizing, we need to stop processing on an NFC boundary, not an
NFD boundary, to support normalizations such as in Bengali, where
appending `U+09D7` to a context of `U+0995 U+09C7` should result in
`U+0995 U+09CC`.
The specification is unclear on this; see https://unicode-org.atlassian.net/browse/CLDR-19218
This also updates the ldml keyboard unit test suite to support running
in full NFC mode (used in all Engine implementations) as well retaining
the NFD mode (now only used by the debugger).
Side note: the Bengali normalization failure case was picked up by the
improvements to the unit test suite, proving once again that good tests
are so valuable.
Fixes: #15491Fixes: #15505
Follows: #15488
Relates-to: CLDR-19218
