Dashboard fixes [Mj-370, MJ-371, MJ-372]

Reduces number of analytics queries by half on the candidate dashboard
Adds users from analytics data to candidate list
Adds description of candidate activity to candidate pages
Only convert microsite and buid lists to sets when required
Merge pull request #640 from DirectEmployers/activity-display-analytics-users

Dashboard fixes [Mj-370, MJ-371, MJ-372]