In phosh, we have broken Cheese (Camera) and Extensions (from GNOME shell)
icons in the launcher. They get dragged in via dependencies, so the
easiest way to disable them is just overruling the .desktop icon. We can
make Cheese visible again in a post-install script (just check if it
points to nodisplay.desktop and delete the link) once we have it working.
Hide icons for terminal programs (htop, nvim, vim) as well as "Firefox
Safe Mode" too. If somebody really wants to use the FF safe mode, they
can do so via terminal.
Have a simple initial version, maybe make it more sophisticated with
UI-specific hidden icons later (right now, it doesn't make sense to
install this in normal GNOME, because there you would need
org.gnome.Extensions). (There is "NotShowIn=phosh" (untested), but using
this would mean that we need to keep all the information of the original
desktop file for the UIs that will display them; we can't just use the
symlink trick. I'm not sure if we want that at all, but it's
definitively over-engineered for now.)
