Fixes #10315.

When filling from layout, if the .kvks file did not exist, an obscure
error was generated:

    Error: 2908 Error encountered parsing eo_plus.kvks: TypeError: Cannot read properties of null (reading 'byteLength')

Fixed this by checking for file existence before attempting to process,
which then reports a more understandable error of 'file not found'.

Then, needed to tweak the caller in Keyman Developer IDE to remove the
reference to the .kvks file before attempting to build
(chicken-and-egg).

auto: increment master version to 17.0.239

feat(developer): escape bad markers 🙀 

chore(core): better reporting in ldml tests 🙀

feat(core): more regex testing 🙀 

fix(core): ldml fixes for normalization between transform groups 🙀

- move prepend_marker out of line
- replace bool for_regex with an enum
- cleanup another instance of \b -> \u0008

#9121

fix(developer): quell internal error when  a section fails 🙀

Merge branch 'chore/core/ldml-test-robust-epic-ldml' into feat/developer/9121-reject-bad-regex-epic-ldml

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

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

auto: increment master version to 17.0.238

chore(developer): honor prompt to upgrade in kmc

feat(developer): Consolidate public APIs for kmc modules

- needed to remove/re-add the “≈≈[\u0001-\uD7FE]” format  (aka LDML_MARKER_ANY_INDEX)

#9121

- escape markers to prevent the n'th marker from having some other meaning

- marker overrun! the 40th marker becomes a parenthesis, breaking regex

feat(core): ldml proper regex implementation 🙀🙀 #9121

- more easily handle test events

- match in a set
- quantifiers

For: #9121

- more err reporting out of inner functions such as key not found
- helper functions for setting FAIL and SKIP actions with messages
- colorization

For: #9121

- the intermediate stages of transforms also need to use marker-safe normalization
- re-enable a test that was failing previously due to this

For: #9468

auto: increment master version to 17.0.237

- when a required section is missing, only throw an internal error IF we haven't already flagged a problem.  for example, if 'vars' fails to compile because of a problem, and we already have an error on file, then don't throw an internal error that 'bksp' depends on uninitialized 'vars'.

- mimic this flow in the test helpers.

- add a test case for this in the test helpers, in test-tran

- add a strictError flag to say that no additional errs are allowed.

Fixes: #10291

fix(common): give warning if emcc.py is present but not executable

fix(oem/fv): Add fv_kwadacha_tsekene

auto: increment master version to 17.0.236

- one disabled for now

For #9468

For #9468

For #9468

- change the common emscripten locator to warn if $EMCC  or $EMSCRIPTEN_BASE/emcc.py is present but not executable
- emscripten v3.1.50 via homebrew seems to be not executable