New parser for event log. Manually parse the outermost EventStream to more easily deal with corrupt or partially written logs.

Changed rtpdump converter and neteq tool to use new parser, but still aborting if the file is corrupt.

Review-Url: https://codereview.webrtc.org/1768773002
Cr-Original-Commit-Position: refs/heads/master@{#12714}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: d5c1a0bd5d1faac10db9986117483d25b9c10b1f
12 files changed