Most tests in columnstore_index_per_path_filters.js don't assert that CSI is actually used but they do explicitly create the columnstore index. This approach makes it somewhat unclear what the tests expect to cover.

Proposal:

1. remove explicit columnstore index creation
2. remove uses_column_store_index tag to allow this test in columnstore job
3. remove feature guard tags
4. split out any of the tests that explicitly depend on using CSI

As a result, the tests will run both with and without CSI ensuring that the semantics they expect match across engines and access paths.

Or we could move the tests in the other direction, that is, make them explicitly CSI-only and add checks about the correct plan selection, etc.