[C++] Handle nulls consistently in set membership tests (Substrait <--> Acero)

### Describe the bug, including details regarding any error messages, version, and platform.

There is a TODO here:
https://github.com/apache/arrow/blob/3c013da56fd55122072ffaca3e23afb12c290075/cpp/src/arrow/engine/substrait/expression_internal.cc#L1284

Now that https://github.com/apache/arrow/pull/36739 is merged, can we use the new [`INCONCLUSIVE` null matching option](https://arrow.apache.org/docs/dev/cpp/api/compute.html#_CPPv4N5arrow7compute16SetLookupOptions20NullMatchingBehavior12INCONCLUSIVEE) to translate Substrait [`SingularOrList` expressions](https://github.com/substrait-io/substrait/blob/651829aabde4c9562b291f8bb444aa0303c482cd/proto/substrait/algebra.proto#L1017) to/from Acero `is_in` function options with consistent null handling behavior?

Can we also use this new option to ensure that [Substrait's `index_in` function](https://github.com/substrait-io/substrait/blob/651829aabde4c9562b291f8bb444aa0303c482cd/extensions/functions_set.yaml#L5) is translated to/from Acero's `index_in` function with the correct options set to give consistent behavior?

Some other related issues:
- https://github.com/apache/arrow/issues/36535
- https://github.com/substrait-io/substrait/issues/517

### Component(s)

C++