fix: handle IS TRUE correctly in EliminateOuterJoin (apache#22444)

## Which issue does this PR close?

- Closes apache#22441.

## Rationale for this change

`EliminateOuterJoin` needs to identify "null-rejecting" columns; a
column is null-rejecting with respect to an expression if a NULL value
in the column yields a NULL or false value for the expression.

This analysis was unsound with respect to `IS TRUE`, `IS FALSE`, and `IS
NOT UNKNOWN` operators: those operators are null-rejecting at the
toplevel of the `WHERE` clause, but they may not be null-rejecting when
nested inside an expression tree. The analysis checked this correctly
for `IS NOT NULL` but neglected to apply similar logic for these other
three operators. This resulted in incorrectly converting outer joins to
inner joins in some cases, producing incorrect query results.

As part of fixing this, this PR also makes a bunch of improvements to
the null-rejection analysis, enumerated below, resulting in more
accurate null-rejection analysis.

## What changes are included in this PR?

* Rename `extract_non_nullable_columns` to
`extract_null_rejecting_columns`: "non_nullable" is a property of a
column, "null-rejecting" is a more complex property describing the
relationship between a column and an expression.
* Use `Operator::returns_null_on_null()` instead of maintaining a
hand-rolled and very incomplete list of null-propagating binary
operators. We now compute null-rejection correctly for arithmetic,
bitwise, and regex operators, for example.
* Handle null-rejection correctly for `Expr::Negative`
* Rewrite the logic for handling `OR` and nested `AND` operators to be
more clear, and also more efficient
* Rewrite and expand comments throughout for clarity
* Add unit and SLT tests

## Are these changes tested?

Yes; new unit and SLT tests added.

## Are there any user-facing changes?

Yes, query result correctness fix.

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Co-authored-by: Kumar Ujjawal <ujjawalpathak6@gmail.com>

Author: neilconway