Issue #3269152 by yogeshmpawar, longwave, catch: Remove element_settings BC layer in ajax.js

core/misc/ajax.es6.js

core/misc/ajax.js

core/misc/cspell/dictionary.txt

...em/tests/modules/js_ajax_test/js/js_ajax_test.ajax.es6.js

...system/tests/modules/js_ajax_test/js/js_ajax_test.ajax.js

...s/system/tests/modules/js_ajax_test/js_ajax_test.info.yml

...tem/tests/modules/js_ajax_test/js_ajax_test.libraries.yml

...ystem/tests/modules/js_ajax_test/js_ajax_test.routing.yml

...tests/modules/js_ajax_test/src/Ajax/JsAjaxTestCommand.php

...em/tests/modules/js_ajax_test/src/Form/JsAjaxTestForm.php

...ctionalJavascriptTests/Ajax/BackwardCompatibilityTest.php