message: fix(Scrollbars): use forward ref to fix demo issue
  Can't construct a query for the property "scrollbars" of "ScrollbarsComponent" since the query
  selector wasn't defined.
diff: @@ -6,6 +6,7 @@ import {
  Output,
  ViewChild,
  ViewEncapsulation,
  + forwardRef,
  } from '@angular/core';
  import {
  Geometry,
  @@ -120,7 +121,7 @@ export class TsScrollbarsComponent {
  /**
  * Access underlying scrollbar directive
  */
  - @ViewChild('scrollbar')
  + @ViewChild(forwardRef(() => PerfectScrollbarDirective))
  public scrollbar!: PerfectScrollbarDirective;
  /**
  