Update to new SDKs

[bartr]

Update to latest Azure SDKs

Update to Key Vault v4.1.0

References #66
References #77

[bartr]

We did a spike on updating the Cosmos SDK and have it mostly working. We have filed the issues with the SDK team.

I added the blocked tag as it will be a month or more until the SDK is ready enough to use. We are keeping the branch, but postponing work for the moment.