Add a StackView around Marketplace to allow extra pages on top

This allows a sort of full-screen pop-up to replace the entire Marketplace window contents, on top of the normal contents. The normal contents are kept as they are, but out of view.

Contributes to issue CURA-8565.

plugins/Marketplace/resources/qml/Marketplace.qml

@@ -42,8 +42,17 @@ Window
         anchors.fill: parent
         color: UM.Theme.getColor("main_background")
 
+        //The Marketplace can have a page in front of everything with package details. The stack view controls its visibility.
+        StackView
+        {
+            id: contextStack
+            anchors.fill: parent
+
+            initialItem: packageBrowse
+
             ColumnLayout
             {
+                id: packageBrowse
                 anchors.fill: parent
 
                 spacing: UM.Theme.getSize("default_margin").height
@@ -185,4 +194,5 @@ Window
                 }
             }
         }
+    }
 }

plugins/Marketplace/resources/qml/PackageDetails.qml

@@ -0,0 +1,10 @@
+// Copyright (c) 2021 Ultimaker B.V.
+// Cura is released under the terms of the LGPLv3 or higher.
+
+import QtQuick 2.15
+import QtQuick.Controls 2.15
+
+Label
+{
+    text: "Test!"
+}

plugins/Marketplace/resources/qml/Packages.qml

@@ -62,10 +62,21 @@ ListView
         }
     }
 
-    delegate: PackageCard
+    delegate: MouseArea
+    {
+        width: parent.width
+        height: childrenRect.height
+
+        onClicked:
+        {
+            contextStack.push(Qt.resolvedUrl("PackageDetails.qml"))
+        }
+
+        PackageCard
         {
             packageData: model.package
         }
+    }
 
     //Wrapper item to add spacing between content and footer.
     footer: Item