Fix Date32 and Date64 literals unparsing for SQLite

[sgrebnov]

SQLite date instead of datetime should be used for Date32 and Date64 literals unparsing, example for TPCH orders table:

SELECT 
    o_orderdate, 
    datetime(757382400, 'unixepoch') AS v1,
    date(757382400, 'unixepoch') AS v2,
    o_orderdate = datetime(757382400, 'unixepoch') AS is_v1_equal,
    o_orderdate = date(757382400, 'unixepoch') AS is_v2_equal
FROM 
    orders o 
WHERE 
    o.o_orderkey = 32418;

select
    n_name,
    o_orderdate
from
    customer,
    orders,
    lineitem,
    supplier,
    nation,
    region
where
        c_custkey = o_custkey
  and l_orderkey = o_orderkey
  and l_suppkey = s_suppkey
  and c_nationkey = s_nationkey
  and s_nationkey = n_nationkey
  and n_regionkey = r_regionkey
  and r_name = 'ASIA'
  and o_orderdate >= date '1994-01-01'
  and o_orderdate < date '1995-01-01'
  and n_name = 'INDIA'
ORDER BY o_orderdate

Before this change (1994-01-01 is missing)

+--------+-------------+
| n_name | o_orderdate |
+--------+-------------+
| INDIA  | 1994-01-09  |
| INDIA  | 1994-03-23  |
| INDIA  | 1994-04-27  |
| INDIA  | 1994-05-20  |
| INDIA  | 1994-05-26  |
| INDIA  | 1994-06-27  |
| INDIA  | 1994-08-06  |
| INDIA  | 1994-08-12  |
| INDIA  | 1994-09-01  |
| INDIA  | 1994-09-17  |
| INDIA  | 1994-09-28  |
| INDIA  | 1994-10-21  |
| INDIA  | 1994-10-24  |
| INDIA  | 1994-12-08  |
| INDIA  | 1994-12-23  |
+--------+-------------+

After

+--------+-------------+
| n_name | o_orderdate |
+--------+-------------+
| INDIA  | 1994-01-01  |
| INDIA  | 1994-01-09  |
| INDIA  | 1994-03-23  |
| INDIA  | 1994-04-27  |
| INDIA  | 1994-05-20  |
| INDIA  | 1994-05-26  |
| INDIA  | 1994-06-27  |
| INDIA  | 1994-08-06  |
| INDIA  | 1994-08-12  |
| INDIA  | 1994-09-01  |
| INDIA  | 1994-09-17  |
| INDIA  | 1994-09-28  |
| INDIA  | 1994-10-21  |
| INDIA  | 1994-10-24  |
| INDIA  | 1994-12-08  |
| INDIA  | 1994-12-23  |
+--------+-------------+