Visibility track key value is no longer the inversion of the bound bHidden property

Regression introduced in UE 5.7. Works correctly in UE 5.6.

Up to UE 5.6, the bool value written to the Visibility track's BoolCurve was the inversion of the underlying bound property (e.g. AActor::bHidden), because the property stores "hidden" semantics while the track represents "visibility" semantics. The inversion was performed by:

   // FVisibilityPropertyTrackEditor::GenerateKeysFromPropertyChanged
   bool KeyedValue = !PropertyChangedParams.GetPropertyValue<bool>();

In UE 5.7, FRegisteredPropertyTrackEditor was introduced (CL 45020694) and now intercepts the key generation path for all property tracks. As a side effect, FVisibilityPropertyTrackEditor::GenerateKeysFromPropertyChanged is no longer invoked, and the inversion is silently dropped. The raw bHidden value is written to the BoolCurve unchanged.

1.  Create a new project from the Third Person template.
2.  Place a BP_ThirdPersonCharacter in the level.
3.  Create a Level Sequence and bind BP_ThirdPersonCharacter to it.
4.  Add a Visibility track to the binding (+ Add -> Actor Hidden In Game).

Expected: Visibility track default value is True (Visible).
Actual:  Visibility track default value is False (Hidden).