Fully anonymize example dataset

[mikabr]

The levante-example-dataset redivis dataset should be more fully anonymized such that it was be accessed without signing the data usage certification. I believe this means removing or masking the user_ids in some way.

[ezhang61]

The user_id has been removed from the users table for the sample dataset. I have implemented a "is_user_id_removed": true, params in the validator. Not sure if the email should be hidden too? I believe the emails are generated randomly and should not contain identical information.

[mikabr]

sorry I wasn't entirely clear – we still want to have a user_id column (in all tables that usually have one), because the example dataset should have the same structure as the real datasets. but the values in that column shouldn't be the real user_ids – I think that replacing them 1-to-1 with other values (e.g. randomly generated strings in the same format), or something like that, would work.

the columns user_groups.user_id, survey_responses.child_id, users.parent1_id, users.parent2_id, users.teacher_id, are currently unaffected but should be treated this way, in addition to the already affected users.user_id, runs.user_id, trials.user_id, and survey_responses.user_id.

tagging @mcfrank and @theresacheng to make sure we're on the same page