Replace System.Data.SqlClient with Microsoft.Data.SqlClient

[tsahi]

Is your feature request related to a problem? Please describe.
Microsoft has announced that future development of their .NET SQL Server driver will be done in Microsoft.Data.SqlClient, released as a NuGet package for both .NET Core and .NET Framework. To keep with the latest developments, we need to use that instead of System.Data.SqlClient.

Describe the solution you'd like
This is mostly a find-and-replace of the namespace once the package is added.

[tsahi]

To prevent a dependency on Microsoft.Data.SqlClient in applications that use Oracle database, we need to refactor DAAB so that the SQL Server support is optional with a separate NuGet package, that will depend on this package.