Converted the listview into a RowLayout

I have no idea why i thought a listview was needed for this when
this was made. The data shouldn't be flicable, so it makes way more sense to
use a row layout

CURA-7480

resources/qml/Menus/ConfigurationMenu/ConfigurationMenu.qml

@@ -4,6 +4,7 @@
 import QtQuick 2.10
 import QtQuick.Controls 2.3
 import QtQuick.Controls.Styles 1.4
+import QtQuick.Layouts 1.3
 
 import UM 1.2 as UM
 import Cura 1.0 as Cura
@@ -37,19 +38,16 @@ Cura.ExpandablePopup
     headerItem: Item
     {
         // Horizontal list that shows the extruders and their materials
-        ListView
+        RowLayout
         {
-            id: extrudersList
-
-            orientation: ListView.Horizontal
             anchors.fill: parent
+            Repeater
+            {
                 model: extrudersModel
-            visible: Cura.MachineManager.activeMachine.hasMaterials
-
                 delegate: Item
                 {
-                height: parent.height
-                width: Math.round(ListView.view.width / extrudersModel.count)
+                    Layout.fillWidth: true
+                    Layout.fillHeight: true
 
                     // Extruder icon. Shows extruder index and has the same color as the active material.
                     Cura.ExtruderIcon
@@ -105,6 +103,7 @@ Cura.ExpandablePopup
                     }
                 }
             }
+        }
 
         // Placeholder text if there is a configuration to select but no materials (so we can't show the materials per extruder).
         Label