Use categories for Tutorials page

Instead of adding the category into the title with "Help: ..." etc, use
the actual categorized view that we already use for examples and
marketplace. Set the corresponding meta data in the manifest file and
read it also for tutorials.

Change-Id: Id9081518c1c0afee8d080af3ca8a5dca5cdde775
Reviewed-by: Christian Stenger <christian.stenger@qt.io>
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@qt.io>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>

src/plugins/qtsupport/examplesparser.h

@@ -45,7 +45,10 @@ QTSUPPORT_TEST_EXPORT Utils::expected_str<QList<ExampleItem *>> parseExamples(
     bool examples);
 
 QTSUPPORT_TEST_EXPORT QList<std::pair<Core::Section, QList<ExampleItem *>>> getCategories(
-    const QList<ExampleItem *> &items, bool sortIntoCategories);
+    const QList<ExampleItem *> &items,
+    bool sortIntoCategories,
+    const QStringList &defaultOrder,
+    bool restrictRows);
 
 } // namespace QtSupport::Internal