terminal: Fix gnome-terminal to work with recent versions

terminal: Fix gnome-terminal to work with recent versions

Currently gnome-terminal just returns straight away, opening a terminal in a new
separate process we have no insight into. For patch resolution, this leads to
spawning many different terminal windows, for pydevshell, it just flashes a window
up and then closes.

We need to block until the command completes but gnome-terminal gives us no way
to do this. We therefore write the pid to a file using a "phonehome" wrapper
script, then monitor the pid until it exits.

[YOCTO #7254]
(also fixing do_devpyshell)

(From OE-Core rev: 76e8ab47c936674b8bb9bf1c48de53b30f5bf74a)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>