EVP: Adapt KEYEXCH, SIGNATURE and ASYM_CIPHER to handle key types better

EVP: Adapt KEYEXCH, SIGNATURE and ASYM_CIPHER to handle key types better

The adaptation is to handle the case when key types and operations
that use these keys have different names.  For example, EC keys can be
used for ECDSA and ECDH.

Reviewed-by: Shane Lontis <shane.lontis@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/10647)