Replace usage of controls label with our custom label

This prevents copy pasting a bunch of parameters that we set by default

resources/qml/ActionButton.qml

@@ -5,7 +5,7 @@ import QtQuick 2.7
 import QtQuick.Controls 2.1
 import QtGraphicalEffects 1.0 // For the dropshadow
 
-import UM 1.1 as UM
+import UM 1.5 as UM
 import Cura 1.0 as Cura
 
 
@@ -127,18 +127,16 @@ Button
             elideWidth: buttonText.width
         }
 
-        Label
+        UM.Label
         {
             id: buttonText
             text: button.text
             color: button.enabled ? (button.hovered ? button.textHoverColor : button.textColor): button.textDisabledColor
             font: UM.Theme.getFont("medium")
             visible: text != ""
-            renderType: Text.NativeRendering
             height: parent.height
             anchors.verticalCenter: parent.verticalCenter
             horizontalAlignment: Text.AlignHCenter
-            verticalAlignment: Text.AlignVCenter
             elide: Text.ElideRight
 
             Binding