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>

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

fix(android): Standardize language ID in language picker menu

We're still getting sporadic test failures with BrowserStack. So per one
discussion online, attempting to run without concurrency to see if it
improves stability.

I note that the video from tests where we "fail to capture" shows a
browser with an error: "Safari Can't Connect to the Server" "Safari
can't open the page "localhost:9879/?id=75185158" because Safari can't
connect to the server "localhost".

https://automate.browserstack.com/dashboard/v2/builds/419c59decb8e12303e45e1f4bad1b945252df532/sessions/19712158833ce57592b66a50433965e4146fc972

fix(windows) Update unit tests for tsf bkspace

Co-authored-by: Eberhard Beilharz <ermshiperete@users.noreply.github.com>

chore(core): fixup km_kbp_event docs

fix(web): enhanced timer for prediction algorithm

auto: increment master version to 16.0.60

fix(windows): Delete both code units when deleting surrogate pairs in TSF-aware apps

Also add a test for surrogate backspace

feat(core): add `km_kbp_event` API endpoint

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

chore: use keyman.com instead of keyman-staging.com

auto: increment master version to 16.0.59

When the windows platform recieves the action for a backspace
it will check to see if the character being delete is a surrogate
pair. If it is and the app is TSF aware app it will need to backspace
twice to remove both parts of the surrogate pair. For legacy apps this
is not required.

feat(common/models): extra Unicode-based wordbreaker unit tests

fix(common/models): reconnects unit tests for worker-internal submodules 🎡

Fixes #7227.

We want to use keyman.com for now even for alpha builds, as
keyman-staging.com is going to be used for transition to Docker-based
hosting, and it will be problematic to try and share that process with
alpha builds.

auto: increment master version to 16.0.58