[UX] CKEditor/Rich text editor image sizing needs to be optional.

When saving content that includes an image, CKEditor adds in the width and height parameters. But if I want my image size to be responsive, I need to omit these in order to apply styles with the style sheet.

I note that using the unofficial contrib module CKEditor Addon fixes this problem and others.

One more issue to add to the META? #1087 CKEditor/Rich text editor follow ups.