Caret moved to the end of paragraph when filling chars removed.

[scofalik]

After fixing issue #3597 editor finally is able to create empty inline tags (like <em></em>) with filling characters, basing on model.Document#selection attributes.

However, there is a bug when user types a letter at such position:
<p>foo<em>&#8203;&#8203;&#8203;&#8203;&#8203;&#8203;&#8203;^</em>bar</p>. After typing one character at such position, all filling characters are (correctly) removed. But the selection is moved to the end of paragraph.

This is a followup issue to #3597 and #3744. It was a hidden bug.

[Reinmar]

I think it's a DUP of #3814.

[Reinmar]

And of https://github.com/ckeditor/ckeditor5-typing/issues/47.

[scofalik]

It is a DUP of https://github.com/ckeditor/ckeditor5-typing/issues/47.