There was no check if anchorNode of selection range is inside an element with CSS class ve-ce-slug.

Adding that check let me simplify logic around a little bit as well.

Bug: 47258

Change-Id: I51bf5e9caecf6a8b4e0f75118a93cfe69a5a6542
Merge "There was no check if anchorNode of selection range is inside an element with CSS class ve-ce-slug."