Security: Upgrade two NuGets (and one dependency) that have been flagged

[cybertyche]

Azure Pipelines is recording the following security vulnerability:
CST-E has determined that this component is not generally safe to use.|Azure.Data.Tables 12.6.1 |Critical

This PR updates that NuGet (and its dependent package Azure.Core. It also updates System.Data.SqlClient, which is being flagged in Visual Studio as a security risk.

Microsoft Reviewers: Open in CodeFlow

[ReubenBond]

Thanks, @cyberenerally. We typically recommend that end users update their own dependencies rather than relying on transitive dependencies to update them, but I will merge this anyway.

[cybertyche]

We typically recommend that end users update their own dependencies rather than relying on transitive dependencies to update them, but I will merge this anyway.

Ah! Interesting. For the SQL Server one, I think that makes sense. The Azure DataTables one was showing as a security risk in the VSO pipeline itself as critical, so my guess is if it wasn't flagged yet for sending you nag mails, it would eventually. That's what happened with my old team in Bing.