SearchFilterTrait Incomplete Field Localization

SearchFilterTrait::getSearchableAttributes() constructs the field label using

'label' => (__d('field', $column) ?? Inflector::humanize($column))

This is not consistent with the implementation of _column_key in Standard/index.php. Specifically, field localizations can be controller specific as well as timezone aware. We should probably take the implementation of _column_key and make it more generally available.