Support txn insert when db sync

[lsy3993]

Txn insert is the SQL which starts with 'BEGIN' and ends with 'COMMIT/ROLLBACK'.

The general SQL may be like this :

insert A + insert B

        begin; 
        insert into t1 select id, '2017-02-28', 'y1' from aaa.test_a where id = 23;
        insert into t2 select id from aaa.test_a where id = 12;
        commit;

insert A + delete B

        begin;
        insert into t1 select id from aaa.test_a where id = 12;
        delete from t2 where user_id = 1;
        commit;

insert A + delete B + update B

        begin;
        insert into t1 select id from aaa.test_a where id = 12;
        delete from t2 where user_id = 1;
        update t2 set city = 'new' where user_id = 2;
        commit;

insert A + update B + delete C

       begin;
       insert into t1 select id from aaa.test_a where id = 12;
       delete from t2where user_id = 1;
       update t3 set name = 'new' where id = 111;
       commit;

Assume that the tables above are all in the db which sync by ccr

[lsy3993]

replated PR is : #234