Trigger a JavaScript deprecation error for dialogClass in forked dialog.js

Re-titling - I figured out the PHP deprecation layer in the other issue, so now this issue is just about whether we want to add a js deprecation too, which seems fine if we can, but also non-critical.

I lost more time than I'd care to admit on a Project Browser issue due to there not being a JS deprecation, so I'm a big +1 on having this done to spare other 10 > 11 upgraders that annoyance.

Updating the issue summary.

Cleaned up issue summary some.

Updated deprecation for 10.4 since 10.3.0 is now out. But deprecation seems fine.

Done

nod_ → closed merge request !8227

Added this issue to the CR: https://www.drupal.org/node/3440844 →

Committed and pushed eeaf9c829e to 11.x and 71230ba40a to 11.0.x and ec9ed86905 to 10.4.x. Thanks!

Had to revert on 10.4.x as there are test failures due to the code still using dialogClass somewhere.

    Remaining self deprecation notices (5)
    
      5x: Javascript Deprecation: dialogClass is deprecated in drupal:10.4.x
    and will be removed from drupal:12.0.0.
        4x in MediaLibraryTest::testAllowedMediaTypes from
    Drupal\Tests\ckeditor5\FunctionalJavascript
        1x in MediaLibraryTest::testAlt from
    Drupal\Tests\ckeditor5\FunctionalJavascript