Settings titles should appear in top area, not content area

[holmesworcester]

Right now settings titles that (like "Notifications" here) are in the content area. They should be in the top bar.

(To reproduce, click the community name in the top left to open settings, then navigate through all the different settings sections.)

Design reference:

• https://www.loom.com/share/94718e9418334addb45aaa9e507a5570
• https://www.figma.com/design/ceybIXGmg8akl9qgBoUrwe/Desktop-settings?node-id=13-37&t=u0q6sQvILPkWLyoc-4