Make several type signatures more permissive of downstream Extra st…

[aweinstock314]

…ructs.

[alexheretic]

Thanks, i need to look at this more closely. One worry is the section default changes, since they look quite breaking. I wonder if there's a way to minimise that.

[alexheretic]

Yeah it doesn't seem too bad a break, but it's still a break.

I'd maybe like to remove some stuff for the next break too, like the legacy mod code. Maybe we should also remove the defaulting to Extra as I wonder if glyph_brush should have an opinion on that at all.

Perhaps we could (also) make a non-breaking version of this, where you maybe have to use with_text/with_extra method so it can be released earlier?