Assign NO_TXN operation type for table in global locks for scheduled queries

NO_TXN operation type has to be assigned while acquiring locks for the table in global locks because this will not add records to COMPLETED_TXN_COMPONENTS table. Currently the record introduced by this lock had writeId as NULL. There was a situation which lead to large number of records in COMPLETED_TXN_COMPONENTS table because these records had writeId as NULL which weren't deleted up by AcidHouseKeeperService/Cleaner and this subsequently lead to OOM errors.