night-light-page: Use AdwBanner
Use an AdwBanner to show the "Temporarily Disabled Until Tomorrow" message. GtkInfoBar is deprecated and AdwBanner improves adaptiveness.
Also:
- Add a mnmemonic to the "Restart Filter" button
- Remove the "infobar_unsupported" GtkInfoBar, because it's no longer needed ever since [1]. It was supposed to be removed in [1], but was accidentally re-added during a code review
[1] 909f0686
Edited by Automeris naranja