[CircleGraph] Introduce 'scrollToSelected' message

This commit introduces 'scrollToSelected' message.

ONE-vscode-DCO-1.0-Signed-off-by: s.malakhov <s.malakhov@partner.samsung.com>

src/CircleGraph/CircleGraphCtrl.ts

@@ -55,6 +55,7 @@ export class MessageDefs {
   public static readonly backendColor = "backendColor";
   public static readonly error = "error";
   public static readonly colorTheme = "colorTheme";
+  public static readonly scrollToSelected = "scrollToSelected";
   // loadmodel type
   public static readonly modelpath = "modelpath";
   public static readonly uint8array = "uint8array";