Use screenScaleFactor to consistently adapt sizes to display pixel ratio

plugins/3MFReader/WorkspaceDialog.qml

@@ -12,11 +12,13 @@ UM.Dialog
 {
     title: catalog.i18nc("@title:window", "Open Project")
 
-    width: 500
-    height: 400
+    minimumWidth: 500 * screenScaleFactor
+    minumumHeight: 400 * screenScaleFactor
+    width: minimumWidth
+    height: minumumHeight
 
-    property int comboboxHeight: 15
-    property int spacerHeight: 10
+    property int comboboxHeight: 15 * screenScaleFactor
+    property int spacerHeight: 10 * screenScaleFactor
 
     onClosing: manager.notifyClosed()
     onVisibleChanged:
@@ -31,7 +33,7 @@ UM.Dialog
     Item
     {
         anchors.fill: parent
-        anchors.margins: 20
+        anchors.margins: 20 * screenScaleFactor
 
         UM.I18nCatalog
         {
@@ -59,7 +61,7 @@ UM.Dialog
         Column
         {
             anchors.fill: parent
-            spacing: 2
+            spacing: 2 * screenScaleFactor
             Label
             {
                 id: titleLabel
@@ -373,7 +375,7 @@ UM.Dialog
             enabled: true
             anchors.bottom: parent.bottom
             anchors.right: ok_button.left
-            anchors.rightMargin:2
+            anchors.rightMargin: 2 * screenScaleFactor
         }
          Button
         {