Create a compatible plugin to work with CKEditor 5

Problem/Motivation

CKEditor 4 reaches its end-of-life on 2023. Drupal 10 core does not support CKEditor 4 anymore, only CKEditor 5.

CKeditor 5 module is available since Drupal 9.5.0.

Proposed resolution

Create a new plugin compatible with CKEditor 5.
Set the Drupal version minimum requirement to Drupal 9.5.0.
Create a new branch 3.0.x and a new release of the ckeditor_bgimage module.