Use required properties to fix some more qmllint warnings

Change-Id: I4489bd55e8777b7bf591c41a21e2b6dfdf9ea996
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

examples/quick/shared/LauncherList.qml

@@ -75,6 +75,7 @@ Rectangle {
             id: launcherList
             clip: true
             delegate: SimpleLauncherDelegate{
+                required property url url
                 onClicked: root.showExample(url)
             }
             model: ListModel {id:myModel}

examples/quick/shared/SimpleLauncherDelegate.qml

@@ -51,6 +51,9 @@ import QtQuick 2.12
 
 Rectangle {
     id: container
+    required property string name
+    required property string description
+
     property Item exampleItem
     width: ListView.view.width
     height: button.implicitHeight + 22
@@ -110,7 +113,7 @@ Rectangle {
                 anchors.leftMargin: 10
                 anchors.right: parent.right
                 anchors.rightMargin: 10
-                text: name
+                text: container.name
                 color: "black"
                 font.pixelSize: 22
                 wrapMode: Text.WrapAtWordBoundaryOrAnywhere
@@ -122,7 +125,7 @@ Rectangle {
                 id: buttonLabel2
                 anchors.left: parent.left
                 anchors.leftMargin: 10
-                text: description
+                text: container.description
                 wrapMode: Text.WrapAtWordBoundaryOrAnywhere
                 color: "#666"
                 font.pixelSize: 12