Substrait: Support for more flexible join condition expressions #6544

Is your feature request related to a problem or challenge?

If you run a roundtrip test on

SELECT d1.b, d2.c FROM data d1 JOIN data d2 ON CAST(d1.b AS int) = d2.e

you'll got the error Error: Internal("invalid join condition expression").

This is due to the lack of support of expressions not in the form AND(f0(...), ..., fk(...)), where fi() is EQ() in the consumer (ref).

Describe the solution you'd like

Support for more arbitrary join condition expressions.

Describe alternatives you've considered

This effort can be incremental. I just wanted to make sure this gets brought up and tracked.

Additional context

No response