This function is used to traverse all the implementations provided by
one provider, or all implementation for a specific operation across
all loaded providers, or both, and execute a given function for each
occurence.
This will be used by ossl_method_construct(), but also by information
processing functions.
Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/9356)