RTP Header Extension: record redefinitions and support error return

Add UMA histogram "WebRTC.PeerConnection.RtpHeaderExtensionRedefinition"
to track how often RTP header extensions are redefined with a different ID.

Add field trial "WebRTC-PayloadTypePicker-ErrorOnRtpExtensionRedefinition"
to enable returning RTCError::InvalidParameter when such a redefinition
occurs.

Propagate FieldTrialsView to RtpHeaderExtensionRecorder to support
the field trial check.

Bug: webrtc:504685269
Change-Id: Ic7a27465c1e08170908b2b49d98494aa6ad96f12
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/473840
Reviewed-by: Danil Chapovalov <danilchap@webrtc.org>
Auto-Submit: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#47744}