Cosmic Text (Continuation of #179)

[LPGhatguy]

Closes #95.

This PR picks up where #179 left off! I didn't do a great job of reviewing this code when @msparkles was working on it, but now I'm hoping to push this work over the finish line.

I created a new branch and PR because I don't have write access to the original repo from #179.

I changed most of the widget APIs to align them when the main branch to make it easier for folks to migrate, including our game. In tandem, I'm working on upgrading our game to support the changes in this PR and using it as a layout test because it's such a big overhaul!

Remaining Issues

• Split premultiplied texture format into separate change
• Split PaintLimits into separate change
• Investigate sizing issues when using expanded alongside this widget
• Audit text alignment inside buttons
• Drag operations that happen outside the textbox bounds always snap to the beginning of the box instead of the nearest position within the box

[LPGhatguy]

Button alignment is currently a little whack. These buttons have a minimum size enforced on them which causes the text to no longer be centered it seems:

[LPGhatguy]

fontdue	COSMIC text