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What's changed and what's your intention?

Supports CTE query, for example:

with cte1 as (select i as j from a), cte2 as (select ref.j as k from cte1 as ref), cte3 as (select ref2.j+1 as i from cte1 as ref2) select * from cte2 union all select * FROM cte3 order by 1;

+----+
| k  |
+----+
| 42 |
| 43 |
+----+

Main changes:

• Remove the duplicate timestamp constraint in Schema.
• If the table is not found, don't throw an error when resolving tables in the SQL planner.
• Adds some CTE test cases.

TODO:

• Some queries are not supported by datafusion, we can create some issues to track them.

Checklist

• I have written the necessary rustdoc comments.
• I have added the necessary unit tests and integration tests.

Close #1315