This commit allows and requires building against libpeas1 versions that
contain the fix for gobject-introspection 1.80 or later

This should re-establish that function for newer X setups.
As we don't know whether the old keycodes could still occur,
we simply keep for compatibility.

Backported from
https://gitlab.gnome.org/GNOME/eog/-/commit/b23508382f0131d9961e437fe8c8453adeb84faa

It turns out that, depending on the responsible GVfs implementation,
a GFileInfo may not actually set the content type attribute even if
requested. Since knowing the content type is rather critical for eom
try to use the fast content type as a fallback in those cases.

The fast content type should be hardly unknown as it is usually just
based on the file extension.

Fixes #360.

Backported from https://gitlab.gnome.org/GNOME/eog/-/commit/de19faf73c8d8627193320d512c8b97316d9740c

This prefers the real content type, but automatically falls back to the
fast content type the other one isn't set in the GFileInfo.

Backported from https://gitlab.gnome.org/GNOME/eog/-/commit/4f80d090fd8f27c8d430dfe5931ea53446643ec7