Add save projects submenu

CURA-7866

resources/qml/Menus/FileMenu.qml

@@ -4,7 +4,7 @@
 import QtQuick 2.2
 import QtQuick.Controls 1.1
 
-import UM 1.2 as UM
+import UM 1.6 as UM
 import Cura 1.0 as Cura
 
 Menu
@@ -37,8 +37,9 @@ Menu
     MenuItem
     {
         id: saveWorkspaceMenu
-        shortcut: StandardKey.Save
+        shortcut: visible ? StandardKey.Save : ""
         text: catalog.i18nc("@title:menu menubar:file", "&Save Project...")
+        visible: saveProjectMenu.model.count == 1
         onTriggered:
         {
             var args = { "filter_by_machine": false, "file_type": "workspace", "preferred_mimetypes": "application/vnd.ms-package.3dmanufacturing-3dmodel+xml" };
@@ -54,6 +55,15 @@ Menu
         }
     }
 
+    UM.ProjectOutputDevicesModel { id: projectOutputDevicesModel }
+
+    SaveProjectMenu
+    {
+        id: saveProjectMenu
+        model: projectOutputDevicesModel
+        visible: model.count > 1
+    }
+
     MenuSeparator { }
 
     MenuItem