Reland "Move VideoQualityAnalyzer to OnFrameDropped callback."

This is a reland of commit a7c29a690e22a2c0edd6f543e580c7f601362061
Problems seen in previous attempt should be addressed as of
https://webrtc-review.git.corp.google.com/c/src/+/449687

Original change's description:
> Move VideoQualityAnalyzer to OnFrameDropped callback.
>
> This deprecates usage of the EncodedImageCallback::DropReason type,
> which was never actually read anyway, and moves this code to the new
> callback method.
>
> Bug: webrtc:467444018
> Change-Id: I105e44237e6f1bf02bd5664cc6a098a2e734c6e9
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/449640
> Reviewed-by: Sergey Silkin <ssilkin@webrtc.org>
> Commit-Queue: Erik Språng <sprang@webrtc.org>
> Cr-Commit-Position: refs/heads/main@{#46913}

Bug: webrtc:467444018
Change-Id: Id61ad42cbaf4d1dc00fbe1338f9d3c203837332e
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/450040
Auto-Submit: Erik Språng <sprang@webrtc.org>
Reviewed-by: Sergey Silkin <ssilkin@webrtc.org>
Commit-Queue: Sergey Silkin <ssilkin@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#46942}