display: Make nightlight widgets clamped to same size as other panels

Done similarly to !1739 (merged), I just added/changed widgets to be libadwaita widgets where appropriate. This makes the size clamping behavior similar to other panels, which use these libadwaita widgets.

I also deleted the mention of the list box in cc-night-light-page.c, because it no longer exists in the UI layout. As far as I can tell, it wasn't used anyways, and I can't see how it would be used. So, I hope that's okay.

Finally, I moved the nightlight temporarily disabled info bar out of the night_light_settings container, as it is clamped to the same size as the actual settings otherwise. I also fixed the formatting on the label, as it appeared to wrap, when that isn't how info bars elsewhere are formatted. Either way, it doesn't seem to show in GNOME anymore, because there's no option to temporarily disable the night light currently.

Appears to solve #2248 (closed).