Revert "Batch SDP candidates and O(1) TransportInfo lookup"

This reverts commit b38573bb56e571405b318c761c23a5b247d24716.

Reason for revert: Broke the chromium roll

Failure Link: https://chromium-review.git.corp.google.com/c/chromium/src/+/8622522?tab=checks

Original change's description:
> Batch SDP candidates and O(1) TransportInfo lookup
>
> SdpDeserialize added candidates one at a time with AddCandidate(), which
> looks up the m= section, copies the candidate and recomputes the
> connection address on every call. SdpSerialize copied the candidates of
> each m= section and looked up its TransportInfo by name.
>
> Now the parser fills one IceCandidateCollection per m= section and
> passes them to SessionDescriptionInterface::Create(), which updates each
> section's connection address once. The serializer reads the candidate
> collections directly and tries the TransportInfo at the same index
> before falling back to a lookup by name.
>
> BM_Sdp* benchmarks (release build, median of 5 runs):
> - Deserialize: -2.9% (small), -4.6% (large)
> - Serialize: -3.7% (small), -12.2% (large)
>
> Bug: none
> Change-Id: I04eae8cab5870cf60708cea9668cc147807ba176
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/509664
> Reviewed-by: Henrik Boström <hbos@webrtc.org>
> Commit-Queue: Tomas Gunnarsson <tommi@webrtc.org>
> Cr-Commit-Position: refs/heads/main@{#49014}

Bug: none
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Change-Id: I361a5616f1d51402b270f8a3d180453b610293d2
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/510940
Bot-Commit: rubber-stamper@appspot.gserviceaccount.com <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: rubber-stamper@appspot.gserviceaccount.com <rubber-stamper@appspot.gserviceaccount.com>
Auto-Submit: Tomas Gunnarsson <tommi@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#49024}