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.
Unfortunately I forgot to update TestCrunchDatasets so I amended the commit and force pushed it and hopefully now I will finally get a successful build.