chore(android/app): Update whatsnew for 17.0

fix(web): U_ key id -> text for all subkeys; is now preprocessed

fix(ios): multiple keyboard slide-in animations on app start

fix(web): keyboard-documentation rendering mode

chore(android): Update targetSdkVersion to 34

auto: increment master version to 17.0.248

chore(developer,core): change sample and test files to use \u{…} 🙀

feat(core): unescape u 🙀

fix(ios): banner image management

Merge branch 'feat/core/10319-escaping-you-epic-ldml' into feat/developer/10319-remove-old-escape-epic-ldml

For: #10319

- don't try to remove irregular sentinel sequences
- update test

For: #10319

- remove stray change to kmx_processevent.cpp
- fix escaping of syntax chars
- fix comment per review

For: #10319

auto: increment master version to 17.0.247

fix(web): right-flick gesture-preview positioning

docs(linux): Add documentation for Core API verification

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

docs(common): Update website README.md

chore(common): Update crowdin strings for Khmer

fix(web): Add null check for changing the keyboard during typing

Closes #10405.

auto: increment master version to 17.0.246

* update configure step about downloading _common/ files
* Add info about website-local-proxy

feat(developer): add `-m` parameter to kmc to control message severity

fix(android): Fix OSK rotation issues

- #10389 will require this, but at least change the test files

#10319