Token annotator for clang-format incorrectly identifies operator& as a reference type in situations like Boost serialization archives.
Add annotation rules for standalone and chained operator& instances while preserving behavior for reference declarations at class scope. Add tests to validate annotation and formatting behavior.
Consider moving ScopeType out of TokenAnnotator and keeping it consistent with the style of LineType above (and replacing TokenAnnotator::ScopeType with ScopeType everywhere).