Enhance auto-remap heuristics: remove 12,197 manual remaps and 160 fn ptr fixups

- Rewrite AST walker to collect ALL typedefs per tag, disambiguate
  multi-typedef tags automatically (no exclusion list needed)
- Add UnwrapType helper for ElaboratedType/AttributedType/ParenType
  sugar types that were hiding typedef-tag and fn-ptr relationships
- Auto-discover function pointer typedef pairs from AST: detect
  FunctionProtoType typedefs and their PointerType aliases, generate
  --remap, --exclude, and --reducePointerLevel entries automatically
- Remove 12,197 of 12,705 manual --remap entries from scraper.settings.rsp
  (508 genuinely manual entries remain: semantic primitives, pointer
  remaps, nested qualifieds, uppercase renames)
- Remove 160 of 184 entries from functionPointerFixups.json
  (24 remain: 6 alreadyPointer, 13 name-only, 5 edge cases)
- Delete remapExclusions.rsp (no longer needed)
- Zero conflicts: auto-discovery never picks wrong name
- Winmd output identical to baseline (24,328,704 bytes)
- All 36 tests pass

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: jevansaks