Change PartDesign Pad and Revolution tree icons

Use the same icons as the toolbar buttons.

src/Mod/PartDesign/Gui/ViewProviderPad.cpp

@@ -36,7 +36,7 @@ PROPERTY_SOURCE(PartDesignGui::ViewProviderPad,PartDesignGui::ViewProviderSketch
 
 ViewProviderPad::ViewProviderPad()
 {
-    sPixmap = "Tree_PartDesign_Pad.svg";
+    sPixmap = "PartDesign_Pad.svg";
 }
 
 ViewProviderPad::~ViewProviderPad() = default;