Change the shellcheck job so that we configure the build and check the
preprocessed versions of the scripts, not the bare ones, which might not
be syntactically valid yet.
Make Doxygen see also macros defined inside struct declarations,
and to include also opaque structs.
Keep members in the order they are in the .h file, since Doxygen's
case-insensitive sort by name jumbles things.
Add an input filter that tries to link e.g.
#define pw_core_add_listener(...) pw_core_method(c,add_listener,...)
to the corresponding declaration in struct pw_core_methods.
