Editor::getFilterFormat() should throw domain error if Editor::format not set

Any takers? I promise reviews :)

Keshav Patel → made their first commit to this issue’s fork.

Created the MR using the #26 patch and addressed comment #35 as well, but the pipeline failed. keeping it on "Needs work".., please review the changes.

Change as per #35:

   /**
    * Returns the filter format this text editor is associated with.
    *
    * @return \Drupal\filter\FilterFormatInterface
    *
    * @throws \DomainException
 -  *   If called without an associated filter format.
 +  *   Thrown if the text editor is called without an associated filter format.
    */
  public function getFilterFormat();

Those are all broken tests. Each of them is creating an Editor config entity without a corresponding FilterFormat already existing. We should fix those tests.

Updating the remaining tasks to point to @Wim Leers' feedback. Thanks!