Add ability to handle custom events on the ToastUI editor
What does this MR do?
This is the 1st iteration for delivering #216640 (closed)
Note: changes in this MR does not include the ability to upload images. Uploading images will be addressed in #218529 (closed)
Changes in this MR adds the underlying boilerplate code for adding/handling of custom events on the ToastUI editor.
Expected behavior
No visual changes are expected from this iteration.
Does this MR meet the acceptance criteria?
Conformity
Edited by Jacques Erasmus