Merge 'feature: INSERT INTO <table> SELECT' from Pedro Muniz

Closes #1528 .
- Modified `translate_select` so that the caller can define if the
statement is top-level statement or a subquery.
- Refactored `translate_insert` to offload the translation of multi-row
VALUES and SELECT statements to `translate_select`
- I did not try to change much of `populate_column_registers` as I did
not want to break `translate_virtual_table_insert`. Ideally, I would
want to unite this remaining logic folding `populate_column_registers`
into `populate_columns_multiple_rows` and the
`translate_virtual_table_insert` into `translate_insert`. But, I think
this may be best suited for a separate PR.
## TODO
- ~Tests~ - *Done*
- ~Need to emit a temp table when we are selecting and inserting into
the Same Table -
https://github.com/sqlite/sqlite/blob/master/src/insert.c#L1369~ -
*Done*
- Optimization when table have the exact same schema - open an Issue
about it
- Virtual Tables do not benefit yet from this feature - open an Issue
about it

Reviewed-by: Jussi Saurio <jussi.saurio@gmail.com>

Closes #1566

core/lib.rs

@@ -421,6 +421,7 @@ impl Connection {
                             &syms,
                             None,
                             &mut table_ref_counter,
+                            translate::plan::QueryDestination::ResultRows,
                         )?;
                         optimize_plan(
                             &mut plan,