test/provider: Add tests for SignMessage and VerifyMessage API

Add tests to perform the new EVP_PKEY_sign_message_xxx() and
EVP_PKEY_verify_message_xxx() API with combined digest and sign
algorithms such as 'ECDSA-SHAxxx' or 'RSA-SHAxxx'.

Signed-off-by: Ingo Franzki <ifranzki@linux.ibm.com>

Author: ifranzki