message: Change zOrder logic when add new data source
diff: @@ -166,7 +166,7 @@ export class Pane implements IDestroyable {
  }
  public addDataSource(source: IPriceDataSource, targetScaleId: string, zOrder?: number): void {
  - const targetZOrder = (zOrder !== undefined) ? zOrder : this._getZOrderMinMax().minZOrder - 1;
  + const targetZOrder = (zOrder !== undefined) ? zOrder : this._getZOrderMinMax().maxZOrder + 1;
  this._insertDataSource(source, targetScaleId, targetZOrder);
  }
  