gpui: Add a standard text example (#30747)

This is a dumb first pass at a standard text example. We'll use this to
start digging in to some text/scale rendering issues.

There will be a ton of follow-up features to this, but starting simple.

Release Notes:

- N/A
e26620d1cfNate Butler committed on 5/16/2025, 3:35:44 PM· committed by GitHubparent9dabf49
30 files changedLine totals unavailable