This is why I insist my customers call me FIRST so I can
professionally cut out a clean hole with a diamond saw,
so a reasonable repair can be made.
In my experience of hundreds of similar tile repairs done
after plumbers, I no longer will mess with working after
them. They are hackers and are generally good at beating
the crap out of the tilework. In your picture it's clear they
removed at least _twice_ as much wall, maybe three times
as much wall needed to do a simple pipe job.

You need to use a grinder with a diamond blade and cleanly
remove the rest of that wall. Replacing the whole single wall,
in my opinion, will be much easier than trying to fix that
butcher job.

Cut out the remaining tile on that wall- cleanly, then you can
install cementboard. You can fasten the correct thickness
of wood strips over the studs to bring out the cementboard to
the original thickness of the old mud-wall, to make it even
with the surrounding walls. Since you want to do a temp
job, you can find a similar wall tile.

Another argument to re-doing the whole valve wall is that it will
look like a reasonably decent shower if you have the two existing
walls finished in the original tile, and the new complete wall
finished in a reasonable matching tile.
It never looks right to try to match a portion of a wall.

Good luck......the plumber really screwed you there.
He should trade in his sledge hammer for a more modern
tool......a diamond saw......

thetiler