[Pre3] Response streaming default and opt-out

[guardrex]

Fixes #34870
Addresses #34948

Notes

• Adds a bit to the existing coverage to include HttpCompletionOption.ResponseHeadersRead.
• Versions in the new coverage for >=10.0.

cc: @campersau

---

Internal previews

📄 File	🔗 Preview link
aspnetcore/blazor/call-web-api.md	aspnetcore/blazor/call-web-api

[guardrex]

@campersau ... In the opt-out case, is ResponseContentRead still the default for HttpCompletionOption? ... and if so, then we don't need to remark on that in the >=10.0 coverage, correct?

[guardrex]

... and this is for Preview 2, correct?

[pavelsavara]

Please confirm that this is for Preview 2.

Probably preview3, but it's not done yet.

[guardrex]

@pavelsavara @campersau ... I think my latest updates to this PR cover everything. Can one or both of you make a final check? ... and please confirm that this is still going to make it for Pre3 (if not, I'll mark it for Pre4).

[pavelsavara]

This would not work for Blazor until dotnet/runtime#97449 is fixed. I don't think we need to worry about it in the preview docs.

[guardrex]

Dan would like the preview docs accurate for a given preview release.

I'll comment out just the <WasmEnableStreamingResponse> description until later, and I'll track on that issue to surface it.

[pavelsavara]

this is still going to make it for Pre3

Yes