MXS-1744 Use gtid querying instead of MASTER_GTID_WAIT when waiting for catchup

MASTER_GTID_WAIT uses gtid_slave_pos when comparing to the target gtid. This creates
problems with multi-domain gtids. It's simpler to just query the server for its
gtids repeatedly. Also, the method is now in MariaDBServer.

server/modules/monitor/mariadbmon/mariadbserver.hh

@@ -150,4 +150,16 @@ public:
      * @return True if log_bin is on
      */
     bool check_replication_settings(print_repl_warnings_t print_warnings = WARNINGS_ON);
+
+    /**
+     * Wait until server catches up to the target gtid. Only considers gtid domains common to this server
+     * and the target gtid. The gtid compared is the gtid_binlog_pos if this server has both log_bin and
+     * log_slave_updates on, and gtid_current_pos otherwise.
+     *
+     * @param target Which gtid must be reached
+     * @param timeout Maximum wait time in seconds
+     * @param err_out json object for error printing. Can be NULL.
+     * @return True, if target gtid was reached within allotted time
+     */
+    bool wait_until_gtid(const GtidList& target, int timeout, json_t** err_out);
 };