Fix pointer-to-member-function param with ref-qualifier (#56219)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/56219

Changelog: [Internal]

Doxygen has a bug where it incorrectly embeds the parameter name of pointer-to-member-function parameters with ref-qualifiers (& or &&) into the type string instead of providing a separate <declname> element.

This caused the snapshot to output `R(folly::dynamic::*)() const asFoo&` instead of the correct `R(folly::dynamic::*asFoo)() const &`.

This diff detects the misplaced name in the type string and reconstructs the correct pointer-to-member declarator.

Reviewed By: cipolleschi

Differential Revision: D98123353

fbshipit-source-id: a3a92c5d3897721f0b97a232fdaa59379b408b29