add user access logging to various endpoints

test plan:
* with cassandra and page views enabled, should be able to
log user access to:
 - course home
 - course modules index
 - outcomes index,
 - assignments index
 - pages index
 - external urls
 - external tools tools

(and be able to view them in the user access report)

* also confirm that visiting the discussions index
does not register multiple views when visiting once

closes #CNVS-15321

Change-Id: I43329b1764cdf0c313f548f6aefa3af26c03f300
Reviewed-on: https://gerrit.instructure.com/42075
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Jeremy Stanley <jeremy@instructure.com>
QA-Review: Jahnavi Yetukuri <jyetukuri@instructure.com>
Product-Review: Hilary Scharton <hilary@instructure.com>