Imageviewer: add button to copy image as data url

Change-Id: Ia30751ebb9b567b22de9d1256bb59aa2116366ba
Reviewed-by: hjk <hjk@qt.io>
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>

src/plugins/imageviewer/imageviewerplugin.cpp

@@ -125,6 +125,12 @@ public:
         &ImageViewer::exportMultiImages,
         tr("Export Multiple Images"),
     };
+
+    ImageViewerAction copyDataUrlAction {
+        Constants::ACTION_COPY_DATA_URL,
+        &ImageViewer::copyDataUrl,
+        tr("Copy as Data URL"),
+    };
 };
 
 ImageViewerPlugin::~ImageViewerPlugin()