ui: added find shortcut to set focus in search view

The shortcut is added to the new Find menubar item and dispatches a MessageFind, which is handled by the
SearchController. QtSearchView assures via the ViewLayout that the view is visible when setting focus on the search box.

src/lib/utility/messaging/type/MessageFind.h

@@ -0,0 +1,20 @@
+#ifndef MESSAGE_FIND_H
+#define MESSAGE_FIND_H
+
+#include "utility/messaging/Message.h"
+#include "utility/types.h"
+
+class MessageFind: public Message<MessageFind>
+{
+public:
+	MessageFind()
+	{
+	}
+
+	static const std::string getStaticType()
+	{
+		return "MessageFind";
+	}
+};
+
+#endif // MESSAGE_FIND_H