Issue #2983516 by Wim Leers: Update CKEditor library to 4.10.0

core/assets/vendor/ckeditor/CHANGES.md

core/assets/vendor/ckeditor/ckeditor.js

core/assets/vendor/ckeditor/lang/bg.js

core/assets/vendor/ckeditor/lang/cs.js

core/assets/vendor/ckeditor/lang/de.js

core/assets/vendor/ckeditor/lang/en-au.js

core/assets/vendor/ckeditor/lang/et.js

core/assets/vendor/ckeditor/lang/fa.js

core/assets/vendor/ckeditor/lang/gl.js

core/assets/vendor/ckeditor/lang/hu.js

core/assets/vendor/ckeditor/lang/ku.js

core/assets/vendor/ckeditor/lang/pl.js

core/assets/vendor/ckeditor/lang/pt-br.js

core/assets/vendor/ckeditor/lang/ro.js

core/assets/vendor/ckeditor/lang/ru.js

core/assets/vendor/ckeditor/lang/sk.js

core/assets/vendor/ckeditor/lang/sq.js

core/assets/vendor/ckeditor/lang/sv.js

core/assets/vendor/ckeditor/lang/tr.js

core/assets/vendor/ckeditor/lang/ug.js