Make floating windows serialize layout realtive to correct content area

com.unity.shadergraph/Editor/Drawing/Manipulators/WindowDraggable.cs

 
             // Recalculate which corner to dock to
             m_WindowDockingLayout.CalculateDockingCornerAndOffset(target.layout, target.parent.layout);
-
-            // Make sure that the window offset is non-negative (remains in screen).
-            Vector2 positionOffset = new Vector2(m_WindowDockingLayout.horizontalOffset, m_WindowDockingLayout.verticalOffset);
-            positionOffset.x = Mathf.Max(positionOffset.x, 0f);
-            positionOffset.y = Mathf.Max(positionOffset.y, 0f);
+            m_WindowDockingLayout.ClampToParentWindow();
 
             // Use the docking results to figure which of left/right and top/bottom needs to be set.
             m_WindowDockingLayout.ApplyPosition(target);

com.unity.shadergraph/Editor/Drawing/Views/GraphEditorView.cs

             if (m_FloatingWindowsLayout == null)
                 m_FloatingWindowsLayout = new FloatingWindowsLayout();
 
-            m_FloatingWindowsLayout.previewLayout.CalculateDockingCornerAndOffset(m_MasterPreviewView.layout, layout);
-            m_FloatingWindowsLayout.blackboardLayout.CalculateDockingCornerAndOffset(m_BlackboardProvider.blackboard.layout, layout);
+            m_FloatingWindowsLayout.previewLayout.CalculateDockingCornerAndOffset(m_MasterPreviewView.layout, m_GraphView.layout);
+            m_FloatingWindowsLayout.previewLayout.ClampToParentWindow();
+
+            m_FloatingWindowsLayout.blackboardLayout.CalculateDockingCornerAndOffset(m_BlackboardProvider.blackboard.layout, m_GraphView.layout);
+            m_FloatingWindowsLayout.blackboardLayout.ClampToParentWindow();
 
             if (m_MasterPreviewView.expanded)
             {