Previous changes for the actions rework introduced new deprecations.

This change modernizes some of our remaining actions in unit tests in

order to avoid some of them, and catches the rest where appropriate.
It also fixes a bug in ActionPlacement.depth that hits a deprecated

code path by checking the action's legacy depth property and not the

ActionPlacement.depth.

All unit tests pass.
Verified that there are no longer any deprecations from action code.