Convert all specs to support vertical search navigation

Currently many specs do not function with the vertical search navigation UI. Each spec should be assessed as to whether it needs to be converted or removed.

This is blocked by !97823 (merged)

The following discussion from !97820 (merged) should be addressed:

• @terrichu started a discussion:

  suggestion (non-blocking): it is strongly suggested to have automated tests for enabled/disabled state for feature flags. Since this MR is rather large already (and I think the spec changes may be significant), I suggest we work on it in a follow up issue and mark that issue as blocking the feature flag release