fix: generate logical plan for UPDATE SET FROM statement

[jonahgao]

Which issue does this PR close?

Example Query：update t1 set name=t2.name from t2 where t1.id=t2.id
It modifies a table using information from other tables.

There is support for this syntax in the code, but it doesn’t actually work.

DataFusion CLI v32.0.0
❯ create table t1(id int, name text);
0 rows in set. Query took 0.032 seconds.

❯ create table t2(id int, name text);
0 rows in set. Query took 0.003 seconds.

❯ update t1 set name=t2.name from t2 where t1.id=t2.id;
Schema error: No field named t2.id. Valid fields are t1.id, t1.name.

Rationale for this change

When a FROM clause is present, what essentially happens is that the target table is joined to the tables mentioned in the from_item list, and each output row of the join represents an update operation for the target table.

Ref: PostgreSQL UPDATE SQL Commands

What changes are included in this PR?

• Join with the from table if exists.
• Use correct schema when parsing AST expressions.

Are these changes tested?

Yes

Are there any user-facing changes?

No

[alamb]

This looks good to me -- thank you @jonahgao

cc @avantgardnerio

[alamb]

Should this expression be cast as well (in case the column type in the source query/table doesn't match the type in the target)?

[jonahgao]

The columns in the None arm are not modified as they do not appear in the assignment map.
For these columns, the old values in the target table will be used, so the data types remain the same.

[alamb]

Thanks again @jonahgao