scanner: prepend protocol name to types symbol

When doing unity builds via meson (example project: https://github.com/swaywm/sway) multiple source files are glued together via #include directives. Having every wayland-scanner generated source file have an identifier named '*types[]' will lead to errors in these unity builds if two or more of these are joined.

Signed-off-by: Marty E. Plummer hanetzer@startmail.com