Remove default app: xterm?

[Bryan Quigley]

Xterm takes up two menu items (xterm and uxterm) and doesn't provide
any more functionality then gnome-terminal.  In an installed setup,
those two menu items make gnome-shell have 3 pages instead of 2 in my
testing.

The comment in seeds for adding it is "Provide a backup terminal and
complete X env.":

Backup terminal - I don't think we really need a backup and we don't
do it for other apps.   There is always a VT and if someone wants to
use a GUI they can install another terminal with gnome-software.

complete X env.  -  Especially with us considering wayland, if it
actually pulls in anything (that other packages don't) then we want to
bring it in explicitly.

Thanks!
Bryan