Split queries on ' read' and 'write` for query response time distribution feature

Add two IS tables QUERY_RESPONSE_TIME_READ and QUERY_RESPONSE_TIME_WRITE for 'read' and 'write' queries correspondingly. The criteria of splitting queries is based on sql command flags, if the flags show that the command CAN change any data then the query is 'write' and 'read' otherwise. As this criteria is based on the possibility but not on the fact of data changing it can be that queries which do not change any data are treated as "write". For example "UPDATE ... WHERE condition" is "write" query even if data were not changed.