Support filtering NUMERIC type

[mkaruza]

No description provided.

[Leo-XM-Zeng]

Should be this time #477 commit, incidentally fix this issue. So this problem can theoretically be turned off

postgres=# create table numeric_test2(empno numeric(4,0), sal numeric(7,2)); 
CREATE TABLE
postgres=# insert into numeric_test2 values(7369,800.00);
INSERT 0 1
postgres=# select * from numeric_test2;
 empno |  sal   
-------+--------
  7369 | 800.00
(1 row)

postgres=# select count(*) from numeric_test2 where empno >= 0.25;
 count 
-------
     1
(1 row)

postgres=# select count(*) from numeric_test2 where sal >= 0.25;   
 count 
-------
     1
(1 row)

postgres=# select * from numeric_test2 where sal >= 0.25;   
 empno |  sal   
-------+--------
  7369 | 800.00
(1 row)