remove document symbols from macro expansion

[FederAndInk]

There is one issue in #674 though that I've completely forgotten about, it does not manage macro expansion eg:

#define M                                                                                \
  namespace ns_name                                                                      \
  {                                                                                      \
  namespace ns_name_impl                                                                 \
  {                                                                                      \
  void f() {}                                                                            \
  }                                                                                      \
  }

M;

may generate this outline:

clangd is showing symbols in macro definition but not in macro expansion

at least we have to exclude symbols from macro expansion, here is a quick PR to detect and remove macro expansion, but it may exist a better implementation

The question is, what do we do with macro expansions? Should we remove them? (like this PR does)

[MaskRay]

This can be folded into ignore for QueryVar::Def

[FederAndInk]

It's a little bit cumbersome, I'll make a commit, so you can see what it looks like, but we would have to edit all ignore functions not just for QueryVar::Def because we want to ignore all symbols generated by macro expansion not just variables.