Add seperator lines for the stageMenu's

CURA-5785

plugins/PrepareStage/PrepareMenu.qml

@@ -69,11 +69,27 @@ Item
                     Layout.fillHeight: true
                 }
 
+                // Separator line
+                Rectangle
+                {
+                    height: parent.height
+                    width: UM.Theme.getSize("default_lining").width
+                    color: UM.Theme.getColor("lining")
+                }
+
                 Cura.QuickConfigurationSelector
                 {
                     Layout.fillHeight: true
                     Layout.fillWidth: true
-                    Layout.preferredWidth: itemRow.width - machineSelection.width - printSetupSelector.width
+                    Layout.preferredWidth: itemRow.width - machineSelection.width - printSetupSelector.width - 2 * UM.Theme.getSize("default_lining").width
+                }
+
+                // Separator line
+                Rectangle
+                {
+                    height: parent.height
+                    width: UM.Theme.getSize("default_lining").width
+                    color: UM.Theme.getColor("lining")
                 }
 
                 Cura.PrintSetupSelector

plugins/PreviewStage/PreviewMenu.qml

@@ -40,7 +40,7 @@ Item
         Row
         {
             anchors.centerIn: parent
-            spacing: UM.Theme.getSize("default_margin").width
+            //spacing: UM.Theme.getSize("default_margin").width
             height: parent.height
 
             Item
@@ -93,6 +93,14 @@ Item
                 }
             }
 
+            // Separator line
+            Rectangle
+            {
+                height: parent.height
+                width: UM.Theme.getSize("default_lining").width
+                color: UM.Theme.getColor("lining")
+            }
+
             Loader
             {
                 // TODO: Make this panel collapsable and ensure it has a standardised background.
@@ -106,6 +114,13 @@ Item
                 source: UM.Controller.activeView != null && UM.Controller.activeView.stageMenuComponent != null ? UM.Controller.activeView.stageMenuComponent : ""
             }
 
+            // Separator line
+            Rectangle
+            {
+                height: parent.height
+                width: UM.Theme.getSize("default_lining").width
+                color: UM.Theme.getColor("lining")
+            }
             Cura.PrintSetupSelector
             {
                 width: UM.Theme.getSize("print_setup_widget").width