Add proper vertical margins (12px) to the SearchEntry widget in the
contacts view to improve spacing and visual consistency. This matches
the existing horizontal margins and follows GNOME design guidelines.
This change improves the visual appearance by preventing the search bar
from appearing cramped, especially when using high-contrast themes.
Closes: https://gitlab.gnome.org/GNOME/calls/-/issues/672
Part-of: <https://gitlab.gnome.org/GNOME/calls/-/merge_requests/762>
Glade misleads us into thinking we need these, but the
property is somewhat confusing in GTK3. In general we don't
want `can-focus` to be true for containers, as that will
break keynav for the children. For non-containers, the
defaults are appropriate.
Instead of manually setting `can-focus`, we should just
use the default values. GTK has sane defaults.
Fixes https://gitlab.gnome.org/GNOME/calls/-/issues/366
