Inform students of information visibilty in preferences

[fsharpseven]

Feature description

Some sort of message on the preferences screen indicating who can access data such as email addresses, phone numbers, etc.

Rationale for adding feature

It appears as if certain data such as email addresses of students can be accessed via the Ion API*, and presumably by the 8th period office and administrators. Regardless of whether or not this functionality will be preserved (#1205), there are no clear/easily accessible indications of exactly who can view your email addresses or phone numbers (especially considering that they aren't really used in Ion and they could be considered personal/private information). While the people who put that information in may not mind, their knowledge of this cannot be assumed.

* It appears through testing that phone numbers are not accessible via the API, however it is still unclear to students who has access to it.

Suggested implementation(s) (if applicable)

• A message indicating who has access to their information and in what way.
• or, removal of those data fields entirely as proposed in #1205.