Gnomit merge request: move buttons to the header bar
To make it work, we have to switch
GnomitWindow to be a
Gtk.Window rather than
Gtk.Dialog, which only makes sense for the main window.
Additionally, this adds the
suggested-action CSS class to the "Commit" button, which makes it look like other "suggested action" buttons throughout the system (i.e. blue on Adwaita).
Here's a screenshot of the new UI (taken while using Gnomit to commit this very change):
For the reference, here's GNOME Language Settings dialog with the same theme (Adwaita Dark):