0023649: Visualization, AIS_LocalContext - make highlighting of already selected...

0023649: Visualization, AIS_LocalContext - make highlighting of already selected objects consistent with and without Shift modifier

1) Add SelectMgr_EntityOwner::IsSelected() and  SelectMgr_EntityOwner::SetSelected() methods to determine if corresponding  entity is selected.
    They replace functionality of SelectMgr_EntityOwner::State() methods that are deprecated now.
2) AIS_InteractiveContext::ToHilightSelected() and AIS_InteractiveContext::SetToHilightSelected() is to be used to enable highlighting of selected objects.
3) By default selected objects are highlighted (new behavior)
4) Add ViewerTest_ViewerCommands: vhighlightselected command to enable/disable 'highlight selected objects' mode.
5) AIS_LocalContext, AIS_InteractiveContext : style changes in Select and ShiftSelect methods.
6) Add test cases /bugs/vis bug23649_1 and  /bugs/vis bug23649_2 to test highlighting of selected objects in local context.
7) Add test cases /bugs/vis bug23649_3 and  /bugs/vis bug23649_4  to test highlighting of selected objects in neutral point.

Updated test case