Contacts.Window: remember width and height of window

According to the change request in issue #9 the contacts application will now store any size changes to the window or if the window has got maximized to the underlaying settings store and will restore the changed dimensions after restarting the app.

GNOME/gnome-contacts#9
1 job for bugfix/issue_9 in 10 minutes and 33 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Build
passed #7661
build-gnome-contacts

00:10:33