shell: Bind the details page's title with its header

Fixes GNOME/gnome-software#1286.
3 jobs for app-name-title in 4 minutes and 28 seconds (queued for 6 seconds)
Status Name Job ID Coverage
  Build
passed debian-stable-x86_64 #1399970

00:02:19

passed fedora-x86_64 #1399969

00:04:28

manual flatpak bundle #1399971
flatpak allowed to fail manual