Adding public report support.
Adding public report support.

For a public report, the user needs to SetSinglePrivilegedRequest in order to access some row data.
To ensure that unauthorized users can't see data they shouldn't, I've also added a check that each TestMetaData is viewable.

BUG=catapult:#3141

Review-Url: https://codereview.chromium.org/2784983002

benschmaus/catapult,catapult-project/catapult-csm,catapult-project/catapult-csm,benschmaus/catapult,catapult-project/catapult,catapult-project/catapult-csm,catapult-project/catapult,sahiljain/catapult,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult,benschmaus/catapult,catapult-project/catapult,benschmaus/catapult,sahiljain/catapult,catapult-project/catapult-csm,catapult-project/catapult-csm,benschmaus/catapult,catapult-project/catapult-csm,catapult-project/catapult-csm,sahiljain/catapult,sahiljain/catapult,sahiljain/catapult,catapult-project/catapult,benschmaus/catapult,sahiljain/catapult,benschmaus/catapult