CCDM: IT's ignore the existence of the Flow.clients.TypeScript

[manolo]

Flow.clients.TypeScript is added by Flow Client so as TB can be notified when the client is loaded or when there is pending work in client router.

Though, there are tests checking different flow features that trust in Flow.client object having only one entry, those tests fail when disabling v14 boostrapper e.g. https://github.com/vaadin/flow/blob/master/flow-tests/test-dev-mode/src/test/java/com/vaadin/flow/uitest/ui/ExportedJSFunctionIT.java#L102

[haijian-vaadin]

should be in beta 2