Consider deprecation (or removal) of `PhysicalExpr::evaluate_selection`

### Is your feature request related to a problem or challenge?

Recent changes in the implementation of `CaseExpr` have replaced the usages of `PhysicalExpr::evaluate_selection` with custom filtering and selective evaluation logic. This was done to avoid overhead introduced by the generic approach `evaluate_selection` takes where it first filters the incoming record batch using the selection vector, calls plain `evaluate` with the filtered record batch, and then expands the result back to the length of the original record batch.

Because of all these changes, `PhysicalExpr::evaluate_selection` is no longer used at all in DataFusion itself. Since it's no longer used, and its use can be a cause of performance overhead, it might be better to deprecate (or even remove) it.

### Describe the solution you'd like

_No response_

### Describe alternatives you've considered

_No response_

### Additional context

`evaluate_selection` was first introduced in #2068

As can be seen from the discussion at https://github.com/apache/arrow-rs/issues/3620 actually implementing selective evaluation more efficiently is not trivial. Does it make sense to have this as an overridable trait function?

Start by locating the PhysicalExpr::evaluate_selection trait method and checking whether any DataFusion implementations or call sites remain; then inspect the CaseExpr selective-evaluation changes described in the issue. Done means reaching and documenting a clear decision on deprecation versus removal, including any affected API users or tests.

Written by the indexing model from the issue text.