TEST: Adapt applicable tests to the changed OSSL_ENCODER_CTX_new_by_EVP_PKEY()

TEST: Adapt applicable tests to the changed OSSL_ENCODER_CTX_new_by_EVP_PKEY()

This adds the convenience function EVP_PKEY_typenames_do_all(), which
does the same as EVP_KEYMGMT_names_do_all(), but without having to
expose all the internal ways to find out if the internal EVP_PKEY key
is legacy or provider-native.

Reviewed-by: Shane Lontis <shane.lontis@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/12873)