Provide non blocking support for binary protocol

While text protocol provides a non blocking api call mysql_send_query (which sends a statement to the server without waiting for response packet), binary protocol has no corresponding api call (prepared statements) which makes asynchronous implementation without internal async api impossible.

Proposal:

Provide a new option MARIADB_OPT_SKIP_READ_RESPONSE which defines if a response from command (text or binary) protocol should be read or not. Additionally mysql->methods structure need to provide a pointer to the function which reads response from statement execution.