Include "gedit" in .desktop keywords

The GNOME Shell search results are forwarded from the results of GLib's g_desktop_app_info_search() function, which matches the Name, Exec, Keywords, GenericName, X_GNOME_FullName, and Comment keys from desktop files[0].

Since gedit is now named "Text Editor", a query for "gedit" would match the "Exec" key and present the application in the search results as expected. Unfortunately that doesn't happen for Flaptaked gedit, which would get its desktop file "Exec" key overwritten to something such as Exec=/usr/bin/flatpak run --branch=stable --arch=x86_64 --command=gedit org.gnome.gedit --new-document

This way, searching for "gedit" when only the Flatpaked version of it is installed returns no results. Searching for "Text Editor" presents the application as expected.

Its been proposed in GLib to parse the "Exec" key for searches but that was rejected[1] because it would imply establishing an API which assumes that the command line behavior of Flatpak would be stable/never-change.

A fix was proposed in Flatpak directly[2] but it was rejected, leaving us with the only option of adding the historical/legacy application names to the "Keywords" key in their desktop files.

Many users, such as myself, have the "muscle memory" of search for the old application's name, such as "gedit", "totem", "evince". Although I agree that the new names should be presented to new users and that the old ones shouldn't be visible in UI, it makes sense and little effort to support the search for the old names IMO.

[0] https://gitlab.gnome.org/GNOME/glib/blob/master/gio/gdesktopappinfo.c#L378 [1] glib#1706 (closed) [2] https://github.com/flatpak/flatpak/issues/2749