[release/8.0] Disable buffering of Blazor streaming responses

[github-actions]

Backport of #53929 to release/8.0

/cc @halter73

Disable buffering of Blazor streaming responses

Description

This change disables response buffering and compression (edit: if compression would cause buffering) for streaming Blazor responses in the same way SignalR does for streaming SSE responses. It checks the state of the QuiescenceTask before writing the initial render to the response body to avoid unnecessarily disabling buffering for non-streaming responses.

Fixes #52323

Customer Impact

Instead of seeing UI update immediately as new content becomes available which is the point of streaming rendering, the streaming component is only rendered after all the content arrives completely. This may be never depending on the design of the application.

This affects customers hosting Blazor apps on servers that buffer responses. This includes App Service and IIS Express in their default configurations. You can work around this by configuring the server to disable compression and buffering as described in the customer reported issue at #52323, but it's not discoverable. Nonetheless at least 5 customers have found this issue already.

Regression?

• Yes
• No

Risk

• High
• Medium
• Low

This change only affects streaming rendering which is new in .NET 8, and it uses a pattern already used by SignalR for SSE responses to disable buffering.

Verification

• Manual (required)
• Automated

Packaging changes reviewed?

• Yes
• No
• N/A