[apps] Shared: Move part of the implementation of TermSumController to

shared (Integral Graph Controller) and improve bound edition in
TermSumController.

apps/shared/vertical_cursor_view.cpp

@@ -0,0 +1,10 @@
+#include "vertical_cursor_view.h"
+
+namespace Shared {
+
+void VerticalCursorView::drawRect(KDContext * ctx, KDRect rect) const {
+  KDCoordinate height = bounds().height();
+  ctx->fillRect(KDRect(0, 0, 1, height), KDColorBlack);
+}
+
+}