Add ability to uninstall any CKEditor plugin

[Safety1st]

It was not an easy task to find out how custom CKEditor plugins could be uninstalled
I had to consult with IPS support. It turns out that you need to open button settings where a button could be deleted:

 

But what if a custom plugin does not have a button? For now it could be deleted only by advanced user using direct link.
I'd like to have an option to uninstall any CKEditor plugin using UI only.