Generated FFI does not have "pathname" populated

[awrichar]

FireFly helps to de-duplicate overloaded methods in an ABI by assigning a "pathname" to each method, if the method name is not unique.

This logic is part of the ResolveFFI method, and is currently only run when an interface is created/saved. It would be easy and beneficial to also run this validation during GenerateFFI, allowing you to preview the generated pathnames instead of leaving them with empty strings.