Add Azure SWA VS deployment

[guardrex]

Fixes #28743

This is temporary coverage to tide us over until the SWA docs receive a tutorial. We'll cross-link to that after it appears and shed this detailed coverage, which is bound to break at some point 💥😈😄.

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Internal previews

📄 File	🔗 Preview link
aspnetcore/blazor/host-and-deploy/webassembly.md	Host and deploy ASP.NET Core Blazor WebAssembly

[guardrex]

@sayedihashimi ... Do you (or perhaps Matt should be pinged) want to look at this PR on SWA VS deployment, meant to tide us over here until a formal SWA docs tutorial goes up later? I'll cross-link to that and remove this when I see the tutorial appear. I'd feel a safer about publishing this if someone familiar with the deployment steps would take a look at this.

[guardrex]

@mkArtakMSFT ... I've tried pinging on and offline without success. Shall we proceed with this as the probably correct guidance? 😄 If so, I already have a tracking item to replace this content with a cross-link when the SWA docs receive guidance on the new VS publishing gesture ... we can go ahead and merge this.