Add Touch support

[DashNY]

Is there a way to add touch support to the demo?
I tried hooking up to the ontouchstart or other ontouch... events but Container.Payload is always null. Any idea?

[chrissainty]

I've not tried using touch events. I'll have a play around with them as soon as I can and if i get something working I'll update the demo.

[ViRuSTriNiTy]

@DashNY You need to add the polyfill provided by mobile-drag-drop as mentioned here: https://github.com/Postlagerkarte/blazor-dragdrop#mobile-devices