Split the action button panel in two different components that are

loaded in different moments.

The SliceProcessWidget is loaded once there is something to slice and it
also shows the process of slicing. The OutputProcessWidget will show the
print information and the actions to do to output the results, such as
Print over network, Save to file, ...

Contributes to CURA-5786.

resources/qml/SliceProcessWidget.qml

@@ -0,0 +1,62 @@
+// Copyright (c) 2018 Ultimaker B.V.
+// Cura is released under the terms of the LGPLv3 or higher.
+
+import QtQuick 2.7
+import QtQuick.Controls 2.1
+import QtQuick.Layouts 1.3
+
+import UM 1.1 as UM
+import Cura 1.0 as Cura
+
+Column
+{
+    id: widget
+
+    spacing: UM.Theme.getSize("default_margin").height
+
+    UM.I18nCatalog
+    {
+        id: catalog
+        name: "cura"
+    }
+
+    property real progress: UM.Backend.progress
+    property int backendState: UM.Backend.state
+
+    Rectangle
+    {
+        id: progressBar
+        width: parent.width
+        height: UM.Theme.getSize("progressbar").height
+        visible: widget.backendState == 2
+        radius: UM.Theme.getSize("progressbar_radius").width
+        color: UM.Theme.getColor("progressbar_background")
+
+        Rectangle
+        {
+            width: Math.max(parent.width * base.progress)
+            height: parent.height
+            radius: UM.Theme.getSize("progressbar_radius").width
+            color: UM.Theme.getColor("progressbar_control")
+        }
+    }
+
+    Cura.ActionButton
+    {
+        id: prepareButton
+        width: UM.Theme.getSize("action_panel_button").width
+        height: UM.Theme.getSize("action_panel_button").height
+        text: widget.backendState == 1 ? catalog.i18nc("@button", "Prepare") : catalog.i18nc("@button", "Cancel")
+        onClicked:
+        {
+            if ([1, 5].indexOf(widget.backendState) != -1)
+            {
+                CuraApplication.backend.forceSlice()
+            }
+            else
+            {
+                CuraApplication.backend.stopSlicing()
+            }
+        }
+    }
+}