Fix policy warnings in project templates

When compiling default created projects with Qt 6.5 and cmake
warnings about Qt policy QTP0001 where issued. This is now
fixed for the project templates. A second patch for the
qtquick-components repo will be provided to get rid of the
remaining policy warnings

Change-Id: Ia701a0cc7e030c9cb1459dc48e5ed2a91a6c6c0e
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

src/plugins/qmlprojectmanager/cmakegen/qmlprojectmaincpp.tpl

@@ -13,7 +13,7 @@ int main(int argc, char *argv[])
     QGuiApplication app(argc, argv);
 
     QQmlApplicationEngine engine;
-    const QUrl url(u"qrc:Main/main.qml"_qs);
+    const QUrl url(u"qrc:/qt/qml/Main/main.qml"_qs);
     QObject::connect(
                 &engine, &QQmlApplicationEngine::objectCreated, &app,
                 [url](QObject *obj, const QUrl &objUrl) {

src/plugins/qmlprojectmanager/cmakegen/qmlprojectmodulecmakelists.tpl

@@ -7,5 +7,6 @@ qt_add_library(%2 STATIC)
 qt6_add_qml_module(%2
     URI "%3"
     VERSION 1.0
+    RESOURCE_PREFIX "/qt/qml"
 %4
 )

src/plugins/qmlprojectmanager/cmakegen/qmlprojectmodules.tpl

@@ -4,6 +4,7 @@
 qt6_add_qml_module(%1
     URI "Main"
     VERSION 1.0
+    RESOURCE_PREFIX "/qt/qml"
     NO_PLUGIN
     QML_FILES main.qml
 )