Fixes: #7220

- do not generate unless version<16.0
- never check checksum

Fixes: #7220

- mark as deprecated

Fixes: #7220

- split validation out into a separate kmx_file_validator.hpp
- kmx_file.h should remain C-only usable

Fixes: #7220

- move VerifyKeyboard into COMP_KEYBOARD::VerifyKeyboard
- change call sites in kmx_file.h

For: #7220

chore(core): verify StartGroup in kmx load 🙀

chore(core): use builder_ for build.sh 🙀

chore: make checksum optional 🙀

chore: merge master into feature-ldml 🙀

chore(web): disable browserstack on non-web-specific builds

chore:  try disabling concurrency for browserstack tests

Merge pull request #7219 from keymanapp/fix/developer/7216-suppress-repeated-warnings-unreachable-code

fix(developer): suppress repeated warnings about unreachable code

fix(developer): compiler mismatch on currentLine

docs(windows): add steps for using testhost debugging

Co-authored-by: Marc Durdin <marc@durdin.net>

This is the first baby step in good verification of a .kmx file. A place
to add more tests.

@keymanapp-test-bot skip

The presence of this file tells CI to use the new builder_ style
parameters for build.sh.

Once all branches for 16.0+ are updated to merge the
chore/core/7247-use-builder-for-build-sh branch, then we can remove this
file and the corresponding bash test branches in CI.

Refactoring of build.sh to use the builder_ functions. The script should
now be a lot cleaner. Usage is available with `core/build.sh --help`

Targets are :x86, :x64, :wasm, :arch (linux/mac).

Supports additional requirements of Linux build (--target-path,
--configure).

By default will attempt to build all available targets.

Actions are: clean, configure, build, test, install, uninstall.

The install and uninstall actions only work for linux and mac targets at
present.

refactor(developer): kmc - encapsulate strs and elem items for sort 🙀

chore(developer): kmc - use local reference for json schema 🙀

refactor(developer): rename `kmldmlc` to `kmc` 🙀

chore(developer): remove name from meta section 🙀

Because BrowserStack tests are unreliable, I am disabling them for any
builds that are not specifically targeting web. Two ways that the tests
can be enabled:

1. Include '(web)' in the PR title
2. Include the label test-browserstack

This only impacts builds in the CI test environment, not anything else.

See build-utils-ci.inc.sh for helper functions for accessing PR
metadata, and build-utils-ci.test.sh for unit tests for this
functionality.

auto: increment master version to 16.0.61