Revamp MIME Type Browser Ex: Replace QObject by Q_DECLARE_TR_FUNCTIONS

When declaring MimetypeModel class, use Q_DECLARE_TR_FUNCTIONS Macro
instead of Q_OBJECT as we only need to call tr() functions.

Task-number: QTBUG-117146
Pick-to: 6.6 6.5
Change-Id: Ic7afd4a806d57ba2a651ebe129f3a91f35764354
Reviewed-by: Ivan Solovev <ivan.solovev@qt.io>

examples/corelib/mimetypes/mimetypebrowser/mimetypemodel.h

@@ -4,13 +4,14 @@
 #ifndef MIMETYPEMODEL_H
 #define MIMETYPEMODEL_H
 
+#include <QCoreApplication>
 #include <QHash>
 #include <QMimeType>
 #include <QStandardItemModel>
 
 class MimetypeModel : public QStandardItemModel
 {
-    Q_OBJECT
+    Q_DECLARE_TR_FUNCTIONS(MimetypeModel)
 public:
     enum Columns { NameColumn, ColumnCount };