Fix `RIGHT/FULL OUTER JOIN ... USING (...)` filter semantics

[KKould]

Related umbrella: #130

Current state

RIGHT/FULL OUTER JOIN ... USING (...) still has filter-semantics gaps after column coalescing.

Expected

Make post-join filtering with USING columns behave correctly for RIGHT / FULL joins.

Pointers

• tests/slt/crdb/join.slt:773
• tests/slt/crdb/join.slt:817
• tests/slt/crdb/join.slt:880