`exclude_using_columns ` might wrongly retain columns from a projected join input

[aalexandrov]

Describe the bug

Currently, the exclude_using_columns called from expand_wildcard doesn't consider the filtering semantics of semi- and antijoins when expanding wildcards on top of joins defined via USING(<columns>) syntax.

From each set of columns equated by a USING(<column>) expression, the code currently (1) sorts the set entries, and (2) retains only the first entry from each set.

Because of that, the columns surviving the exclude_using_columns call might be wrongly chosen from the filtering side if the table qualifier from that side is sorted before the filtered side qualifier.

To Reproduce

For example, given this schema of two identical tables:

create table s(x1 int, x2 int, x3 int);
create table t(x1 int, x2 int, x3 int);

One would expect that the schema of queries where the s and t names are swapped will be identical. However, currently this is not the case:

-- Q1 schema: x1 int, x2 int, x3 int (because s < t)
select * from s left semi join t using (x1);

-- Q2 schema: x2 int, x3 int (x1 is wrongly excluded because t < s)
select * from t left semi join s using (x1);

Expected behavior

I expect the schemas of Q1 and Q2 to be identical.

Additional context

I have a fix for that, for which I will open a PR shortly.