Align out extension naming with other unstable wayland protocols.
The unstable protocols from the wayland-protocols repo are prefixed
with a zwp additionally we keep a e prefix for now as we are still
developing this here. No functional change, just rename.
Pointed out by Derek that the session-recovery interface name is a
bit to generic here.
For now these are generated externally by wayland-scanner and added here.
Also keep the original xml protocol file here for now.
This covers the client side for applications while the server side code
sits with E as compositor.