Remove paragraphs containing only nbsps
In the Editoria Typescript reduce step, we remove paragraphs that contain only whitespace elements. For example, a paragraph with only spaces will be removed: <p> </p>.
We should extend this to include nbsps in the definition of ws-only elements: U+00A0, NO-BREAK SPACE [NBSP].
The end result should be that a paragraph containing only nbsp(s) should be removed by typescript reduce