Added class OperationBar

The OperationBar is a widget which offer the user the possibility to use
all the loaded operations.

app/Widgets/OperationBar.cpp

+#include "OperationBar.h"
+
+OperationBar::OperationBar() {
+}
\ No newline at end of file

app/Widgets/OperationBar.h

+#ifndef EIIMAGE_OPERATIONBAR_H
+#define EIIMAGE_OPERATIONBAR_H
+
+#include <QTreeView>
+
+class OperationBar : public QTreeView
+{
+  Q_OBJECT
+  public:
+    OperationBar();
+  protected:
+  signals:
+};
+
+#endif