Restore ViewObject implementation for all Draft objects

In my tests the code works fine. Using @AIRCAP's instructions,  I have created a 'broken' file from draft_test_objects.FCStd.

src/Mod/Draft/draftobjects/point.py

@@ -31,15 +31,15 @@ import math
 from PySide.QtCore import QT_TRANSLATE_NOOP
 
 import FreeCAD as App
-
 from draftobjects.base import DraftObject
+from draftutils import gui_utils
 
 
 class Point(DraftObject):
     """The Draft Point object."""
 
     def __init__(self, obj, x=0, y=0, z=0):
-        super(Point, self).__init__(obj, "Point")
+        super().__init__(obj, "Point")
 
         _tip = QT_TRANSLATE_NOOP("App::Property", "X Location")
         obj.addProperty("App::PropertyDistance", "X", "Draft", _tip)
@@ -56,6 +56,10 @@ class Point(DraftObject):
 
         obj.setPropertyStatus('Placement', 'Hidden')
 
+    def onDocumentRestored(self, obj):
+        super().onDocumentRestored(obj)
+        gui_utils.restore_view_object(obj, vp_module="view_point", vp_class="ViewProviderPoint")
+
     def execute(self, obj):
         base = obj.Placement.Base
         xyz_vec = App.Vector(obj.X.Value, obj.Y.Value, obj.Z.Value)