LibWeb: Implement read a chunk concept for ReadableStreamDefaultReader

Author: https://github.com/kennethmyhra
Commit: 34ecc59508
Pull-request: https://github.com/SerenityOS/serenity/pull/24132
Reviewed-by: https://github.com/shannonbooth
Reviewed-by: https://github.com/trflynn89

Userland/Libraries/LibWeb/Streams/ReadableStreamDefaultReader.h

@@ -79,6 +79,7 @@ public:
 
     JS::NonnullGCPtr<JS::Promise> read();
 
+    void read_a_chunk(Fetch::Infrastructure::IncrementalReadLoopReadRequest& read_request);
     void read_all_bytes(ReadLoopReadRequest::SuccessSteps, ReadLoopReadRequest::FailureSteps);
     void read_all_chunks(ReadLoopReadRequest::ChunkSteps, ReadLoopReadRequest::SuccessSteps, ReadLoopReadRequest::FailureSteps);
     JS::NonnullGCPtr<WebIDL::Promise> read_all_bytes_deprecated();