optimizer: table scan schema should include row handler

[skyzh]

Currently, the implementation of TableScan's schema is not correct.

https://github.com/risinglightdb/risinglight/blob/c221b085ceb4a61fe1cf1e6c9d6caa36b7215a2e/src/optimizer/plan_nodes/logical_table_scan.rs#L75-L77

When with_row_handler is enabled, we should have an extra i64 column for row handlers at the end.

[xuyifangreeneyes]

Can I have a try on this?

[skyzh]

Thanks! By the way, currently there are no way to test if an executor's schema is consistent with its data chunk outputs. So you may simply change the schema (according to with_row_handler), and don't need to write any tests. If you want, you may also have a look at https://github.com/risinglightdb/risinglight/issues/430.