As WebRTC now supports C++17, simplify the code of dcSCTP by binding return values from std::pair or std::tuple to separate names. Bug: webrtc:13220 Change-Id: Ie49154ff4c823e1528deaef7e372cbc550923bc2 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/246442 Reviewed-by: Danil Chapovalov <danilchap@webrtc.org> Commit-Queue: Victor Boivie <boivie@webrtc.org> Cr-Commit-Position: refs/heads/main@{#35773}