ENCODER: Add support for OSSL_FUNC_encoder_does_selection()

ENCODER: Add support for OSSL_FUNC_encoder_does_selection()

OSSL_FUNC_encoder_does_selection() is a dispatchable encoder implementation
function that should return 1 if the given |selection| is supported by an
encoder implementation and 0 if not.  This can be used by libcrypto
functionality to figure out if an encoder implementation should be
considered or not.

Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/13167)