ui-utils: port the password storage helper to GtkPopover

GtkMenu and friends are all gone from Gtk4.
6 jobs for lr/gtk-4.0 in 10 minutes and 38 seconds (queued for 5 seconds)
Status Name Job ID Coverage
  Build
passed fedora28_dist #1568434

00:03:39

 
  Test
passed centos7 #1568439

00:06:58

passed fedora_autotools_full #1568438

00:03:24

passed fedora_autotools_minimal #1568437

00:02:37

passed fedora_meson_full #1568436

00:03:12

passed fedora_meson_minimal #1568435

00:02:33