Add more materials from Marketplace menu button

This commit adds a button "Add more materials from Marketplace" in the
menu that pops up in the material list while configuring the materials
into custom ones. The button redirects the user to the Marketplace
materials page (https://marketplace.ultimaker.com/app/cura/materials)

CURA-7027

resources/qml/Actions.qml

@@ -54,6 +54,7 @@ Item
     property alias manageProfiles: manageProfilesAction;
 
     property alias manageMaterials: manageMaterialsAction;
+    property alias marketplaceMaterials: marketplaceMaterialsAction;
 
     property alias preferences: preferencesAction;
 
@@ -188,6 +189,14 @@ Item
         shortcut: "Ctrl+K"
     }
 
+    Action
+    {
+        id: marketplaceMaterialsAction
+        onTriggered: Qt.openUrlExternally("https://marketplace.ultimaker.com/app/cura/materials")
+        iconName: "configure"
+        text: catalog.i18nc("@action:inmenu", "Add more materials from Marketplace")
+    }
+
     Action
     {
         id: updateProfileAction;

resources/qml/Menus/MaterialMenu.qml

@@ -157,4 +157,11 @@ Menu
     {
         action: Cura.Actions.manageMaterials
     }
+
+    MenuSeparator {}
+
+    MenuItem
+    {
+        action: Cura.Actions.marketplaceMaterials
+    }
 }