Try: Use non-breaking space override globally

[kjellr]

A followup to #463.

This PR takes the   font override from our editor styles and applies it to the front end as well. It aligns the width of Hoefler Text non-breaking spaces in Chrome with their width in other browsers, and if all goes well, it should have no effect on the front end except when viewing a site in Chrome on a Mac.

In that case, you'll notice that &nbsp characters are shorter. For instance, nested submenu items will appear differently:

Before

After

[jasmussen]

I think this is good. Ship it.

Even if the fix can be further improved or even deprecated at some point, this consistency will be a good start.

[kjellr]

Thanks!