Blazor WASM security updates

[guardrex]

Fixes #19803

Thanks @taylorchasewhite! 🚀

The enhancements include ...

• Flesh out a Graph API call from a component that's based on a named HttpClient. The existing content is generic for a named client and a custom AuthorizationMessageHandler class. This new example (AAD mobile phone number in component code) shows a specific implementation with those features that will work in a real app.
• Add a customize the user example (claims for users) based on Graph API. The existing customize the user coverage only deals with an access token claim (amr) that doesn't require a separate access token request. This new example (a claim for the AAD mobile phone number), similar to the example in the AAD groups and roles topic, shows a specific implementation with a separate Graph API call that will work in a real app.
• Improve topic cross-links, including from the WASM overview topic.
• Fix up a few other nits in other text+examples.

I'm going to wait before engaging further with data storage. The State management topic focuses on it, so let's take more feedback before working further with it. I'll review that topic in detail later ... hopefully in the holidays 🎁 period after .NET 5 releases.