DataRowCollection: Set operations

[logiclrd]

This PR adds functionality on top of the DataSet assertions which was originally written for #1812 but which got moved out for its own independent pull request/evaluation. The changes add some set assertions to the collection types, modelled after the generic collection set operations, and include unit tests and documentation.

IMPORTANT

• The code complies with the Coding Guidelines for C#.
• The changes are covered by unit tests which follow the Arrange-Act-Assert syntax and the naming conventions such as is used in these tests.
• If the PR adds a feature or fixes a bug, please update the release notes with a functional description that explains what the change means to consumers of this library, which are published on the website.
• If the PR changes the public API the changes needs to be included by running AcceptApiChanges.ps1 or AcceptApiChanges.sh.
• If the PR affects the documentation, please include your changes in this pull request so the documentation will appear on the website.

[jnyrup]

Please open a new issue where we can discuss only the APIs.
Separating API review from implementation API is less time-consuming for us, and hopefully also for you.

I'm writing guidelines for this as we speak, but https://github.com/dotnet/runtime/blob/main/docs/project/api-review-process.md should provide the gist of it.

[logiclrd]

I have created an issue: #1896.

[jnyrup]

Closing as API proposal was closed