rtcp::ReportBlock class is designed for serialization while ReportBlockData designed for passing report block information across multiple components. This slightly reduce how RtcpTransceiver and RtcpReceiver interact with other webrtc components Bug: webrtc:8239 Change-Id: I582e3d7b32dc6357954b29a1def37e2e72116a74 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/304285 Commit-Queue: Danil Chapovalov <danilchap@webrtc.org> Reviewed-by: Emil Lundmark <lndmrk@webrtc.org> Cr-Commit-Position: refs/heads/main@{#40006}