Add compatibility test for hidden (second pass)

[eerxuan]

Part of #45.

Category: core / indexes / properties

Add compatibility test coverage for the hidden feature.

Note: a smoke test exists; comprehensive compatibility test coverage is needed.

[vic-tsang]

/take

[github-actions]

Assigned to @vic-tsang!

[eerxuan]

Comprehensive compatibility tests now exist on main (beyond the smoke test); closing.