Add census submissions to contact rollups

[bencodeorg]

Tested locally by importing a large volume (~1 million) of pegasus.forms Petition submissions and all census_submissions. Confirmed:

• counting the number of unique entries in contact_rollups_daily where forms_submitted includes Census aligns with the unique number of entries in census_submissions
• the number of emails with "Teacher" in roles with a census submission aligns with the number of teachers who submitted the census (according to submitter_role field)
• emails who filled out both the Census and the Petition (identified via production query) are listed as having filled out both forms.

This PR does not:

• update the roles_submitted field -- I feel like this needs some broader discussion with the marketing team around what they use.

Outstanding questions:

• does the "upsert" (ON DUPLICATE KEY in insert_from_dashboard_census_submissions) cover enough fields? I only update the forms_submitted field, as I'm not totally clear what fields are/aren't updated when data is updated from other sources.

[jeremydstone]

LGTM

[bencodeorg]

Jeremy suggested offline creating a couple User accounts locally with the same email addresses that appear in census_submissions to make sure that data overwrites/updates work appropriately.

[bencodeorg]

Confirmed a Teacher user account who submitted the census form with another role maintains the role Teacher and the forms_submitted = "Census".