Remove notion of installing cloud assets as preview
Cloud assets are either on disk or not, this preview state confuses stuff without any real benefit. The important thing is that the references get stored in the assets - which they're not going to if we're not installing the cloud assets.
Asset picker previews cloud sounds
Call OnAssetHighlighted when highlighting cloud assets in picker
Add (hidden) to cloud packages that are hidden
Preview sounds when clicking on them in cloud browser
Get rid of the package download notice (if we want this, we have to find a less abrasive way)