quartz: gtk-application - inhibit openFiles events from cmdline

quartz: gtk-application - inhibit openFiles events from cmdline

When an application is started via cmdline, then openFiles events
from MacOS are generated although gtkapplication already interprets
the cmdline arguments and opens suitable arguments as files. So they
would be opened twice. Depending on the exact situation the
openFiles event can also be issued before the startup signal
is given. Depending on the application this can result in a crash
due to unexpected behaviour. I took this idea from the
gedit-app-osx.m file. Also from Jesse van den Kieboom.

See:
https://gitlab.gnome.org/GNOME/gtk/-/merge_requests/2098#note_842975
https://gitlab.gnome.org/GNOME/gtk/-/commit/a3ad7fa80f764fb7bcbe
https://gitlab.gnome.org/GNOME/gedit/-/blob/master/gedit/gedit-app-osx.m#L592