Do you mean open to 90 degrees and where the sash in open position will be tight against the frame?
if so the mega egress hinge will do that
https://windowware.co.uk/trojan-mega-egress-easy-clean-friction-hinge-prc0000017
whether it will fit your window upvc profile or not is another question and whether the Euro groove is in the right place.
if your window has a mullion you can’t remove it now, but French windows are available in upvc.
if you the windows to open back flat against the wall you can’t do that with any upvc system