Begin removal of Access Context Auditing code

The Access Context Auditing code has sat unused for some time, and
should be removed. This code was active for a period of time, and so
some stable users will have a database in their profile directory.

This CL removes the bulk of the code, but leaves a shell which simply
removes the database file on service startup. The service remains
created on startup, and browser tests are left to test this behavior.

Some functions on the PageSpecificContentSettingsDelegate, which were
introduced exclusively to support context auditing, are also removed.
Tests which were making use of them are adjusted to use functions
which are fired at the same time.

Bug: 1101675
Change-Id: I9a12fb97782540aa17bb81037ecb3f291eb9159b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4620527


Commit-Queue: Theodore Olsauskas-Warren <sauski@google.com>
Reviewed-by: Colin Blundell <blundell@chromium.org>
Reviewed-by: Christian Dullweber <dullweber@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1159583}