0030674: Visualization, AIS_InteractiveObject - fix accessibility of several properties

AIS_InteractiveObject/SelectMgr_SelectableObject/PrsMgr_PresentableObject
- added missing getters;
- removed redundant private sections;
- improved documentation;
- AIS_InteractiveObject::Compute() marked as pure interface;
- methods within this hierarchy have been moved to the base class, when reasonable.

Removed redundant typedefs to pointers (PrsMgr_PresentationPointer, PrsMgr_PresentableObjectPointer).

src/AIS/AIS_InteractiveContext.hxx

@@ -454,6 +454,7 @@ public: //! @name iteration through detected entities
 public: //! @name Selection management
 
   //! Sets the graphic basic aspect to the current presentation of ALL selected objects.
+  Standard_DEPRECATED ("Deprecated method - presentation attributes should be assigned directly to object")
   Standard_EXPORT void SetSelectedAspect (const Handle(Prs3d_BasicAspect)& theAspect,
                                           const Standard_Boolean           theToUpdateViewer);