Load any assets using resource serving mechanism

[exyi]

As of v1.1 we have nice cache-friendly content serving mechanism - it should be possible to use images (video, audio and other content) as proposed in the PR #271. Maybe we could use special url that will point to the resource, like resource://my-image or ~~my-image and it will be translated to resource's location. I'm not sure about the url format, but I'd use IDotvvmRequestContext.TranslateVirtualPath to transform it.

We could also add virtual resources for entire image folder to avoid registration hell - could be used like images:delete-icon.png.