In the Streamable mode, why does the Accept header need to support both TEXT_EVENT_STREAM and APPLICATION_JSON simultaneously? Instead of specifying APPLICATION_JSON to receive a JSON response and TEXT_EVENT_STREAM to receive a streaming response.

[JHWang-1997]

Please do a quick search on GitHub issues first, the feature you are about to request might have already been requested.

Expected Behavior

In streamableHttp mode, the response to a request is always returned as a stream, and whether the response should be negotiated between the client and server is determined accordingly. When the client supports TEXT_EVENT_STREAM and the server requires a streaming response, a streaming response is used. When the client only supports APPLICATION_JSON, a JSON message should be responded with.

Current Behavior

The response of a streamable HTTP request is always streamed.

Context

[quaff]

See #521 (comment)