Remove "Labor Meetings" from participation history for CELTS students and track it separately

[Karina-Agliullova]

The screenshot here shows a student’s participation history, and this is a CELTS student, so it shows many labor meetings. If an event is checked as "For Labor students only", remove those events from the Participation history. We should track attendance for Labor meetings elsewhere, such as printing out a report for the semester's meetings to date

[Karina-Agliullova]

https://trello.com/c/GgOLjJtw/1075-remove-labor-meetings-from-participation-history-for-celts-students