Add net log events for device bound sessions

This CL adds two new net log events:
- DBSC_REQUEST gives the parameters of the device bound session
  containing an HTTP request.
- CHECK_DBSC_REFRESH_REQUIRED gives details about whether a request was
  deferred in order to refresh a device bound session.

Bug: 382557887
Change-Id: I3c8bb8c2025103baacde49f6a9769c23fb44843a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6090735
Reviewed-by: mmenke <mmenke@chromium.org>
Commit-Queue: Daniel Rubery <drubery@chromium.org>
Reviewed-by: Kristian Monsen <kristianm@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1396052}