Part/Sketcher: Grid - set grid orientation

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Extend ViewProviderGridExtension so that it is aware of the absolute direction of the XY plane on which the grid is to be drawn.

Fix the calculation of the cam origin.

src/Mod/Sketcher/Gui/ViewProviderSketch.cpp

@@ -2844,6 +2844,8 @@ bool ViewProviderSketch::setEdit(int ModNum)
     this->attachSelection();
 
     auto gridnode = getGridNode();
+    Base::Placement plm = getEditingPlacement();
+    setGridOrientation(plm.getPosition(), plm.getRotation());
     addNodeToRoot(gridnode);
     setGridEnabled(true);