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 think this should be added to the null committer also because this requires the dataset to also be MergeAble for MR to work.