Add some ECH-targetted metrics to QUIC

Like the TCP versions, these metrics let us slice connection error and
latency just to ECH-capable hosts.

Bug: 1287248
Change-Id: I8947a8958a06b90c95ead8f30b4086a72e9b9c6f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4545411


Reviewed-by: David Schinazi <dschinazi@chromium.org>
Commit-Queue: David Benjamin <davidben@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1147352}