CRM-12607 - Add employer and address fields to the Event Participants List report

I have tried at least 5 times to generate this pull request with only my one commit, but I always ended-up having all commits made today on the upstream repo part of it. I really do not know why, my only contribution in this PR is the CRM-12607 commit.

Nevertheless, merging this PR should be straightforward since you have already merged these other commits in.