Remove references to legacy visibility system (#4441)

* remove look at interpolation position

Signed-off-by: hultonha <hultonha@amazon.co.uk>

* remove visibility switch

Signed-off-by: hultonha <hultonha@amazon.co.uk>

* remove references to object cache

Signed-off-by: hultonha <hultonha@amazon.co.uk>

* add some more asserts to catch code that should never run

Signed-off-by: hultonha <hultonha@amazon.co.uk>

* add missing [[maybe_unused]]

Signed-off-by: hultonha <hultonha@amazon.co.uk>

* revert clang-format change

Signed-off-by: hultonha <hultonha@amazon.co.uk>

Code/Editor/Include/IDisplayViewport.h

@@ -35,8 +35,6 @@ struct IDisplayViewport
     */
     virtual float GetDistanceToLine(const Vec3& lineP1, const Vec3& lineP2, const QPoint& point) const = 0;
 
-    virtual CBaseObjectsCache* GetVisibleObjectsCache() = 0;
-
     enum EAxis
     {
         AXIS_NONE,