CDK-451: View isReady / signalReady

This PR builds on https://github.com/kite-sdk/kite/pull/98 and https://github.com/kite-sdk/kite/pull/99 adding support for isReady / signalReady on Views.
I don't think we should be using the partition API since it is going away. You should be able to use the path conversion code to get this without as much work opening a new dataset.