theme, frames: Use surface device scale instead of cairo_scale

theme, frames: Use surface device scale instead of cairo_scale

Bug-Ubuntu: https://bugs.launchpad.net/ubuntu/+source/mutter/+bug/1764554
Bug-GNOME: https://gitlab.gnome.org/GNOME/mutter/issues/99
Forwarded: yes, https://gitlab.gnome.org/GNOME/mutter/merge_requests/61

Gtk now is caching the themed cairo surfaces, then as per
commit gtk@e36b629c the surface device scale is used to figure
out the current paint scaling.

Without this when using background-image's for window buttons
the -gtk-scaled icons isn't properly resized.

Fixes #99

Gbp-Pq: Name theme-frames-Use-surface-device-scale-instead-of-cairo_sc.patch