Roll Blazor into the Simple Auth article

[guardrex]

Fixes #35816

This is still a bit draft-y at the moment, but this is a good spot to stop and discuss the direction.

Initial goals ...

• General guidance and example improvements.
• Add ✨ Blazor goodness ✨.
• Drop the RP sample app ... not necessary ... bloating the repo ... not maintained.

cc: @tdykstra (article metadata author) and @wadepickett for discussion

Dan, you stated ...

For consistency, this content should be consolidated into authn-and-authz docs that live under the corresponding areas for those technologies. In cases where we use these technologies to demonstrate general authorization concepts, we should instead use Minimal APIs & Blazor to demonstrate those concepts.

Thus far, this PR only overhauls the coverage in-place and discusses the UI stacks in the existing article.

There's no separate or pivoted MVC/RP authn-and-authz docs yet (no node/folder of such articles).

Just need to confirm that I should create separate MVC and RP articles on simple auth in their UI stack areas or create one separate MVC/RP article on simple auth somewhere in the UI stack area.

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Internal previews

📄 File	🔗 Preview link
aspnetcore/razor-pages/index.md	aspnetcore/razor-pages/index
aspnetcore/security/authentication/identity-configuration.md	aspnetcore/security/authentication/identity-configuration
aspnetcore/security/authentication/identity.md	aspnetcore/security/authentication/identity
aspnetcore/security/authentication/index.md	aspnetcore/security/authentication/index
aspnetcore/security/authorization/policies.md	aspnetcore/security/authorization/policies
aspnetcore/security/authorization/secure-data.md	aspnetcore/security/authorization/secure-data
aspnetcore/security/authorization/simple.md	aspnetcore/security/authorization/simple