As we add more rust crates in performance-critical places,
we run into some performance issues with debug builds.
This makes it hard to get a good feel for the performance
of the application, as something may be slow simply because
it's not been optimized by the compiler.
This commit adds a ci profile to our meson options,
and adjusts our CI configuration to use it. Regular
builds should continue to use the development profile.
Also renames `default` to `release`
The initial commit of gnome-image-viewer.
Things are in an MVP state, with image viewing and
opening from the desktop functional. We also can
open images externally, print them, and set them as
backgrounds.
