Merge pull request #212 from ckeditor/ci/1636

Other: Aligned the `<CKEditor>` component API to use the new lock mechanism when enabling/disabling the read-only mode.

MAJOR BREAKING CHANGE: Due to introducing the lock mechanism for the `Editor#isReadOnly` property, the `<CKEditor>` component uses the new way of enabling the read-only mode in the editor. The component requires an instance of CKEditor 5 in version 34 or higher. See ckeditor/ckeditor5#10496.

Author: pomek