Add information to signup form and profile management for which data is visible for whom

[cahfofpai]

At the signup and profile management form various data is requested from the volunteers. There are differences in which data can seen by all volunteers (e.g. the full name) and which only by the organizers (e.g. the phone number).

It would be helpful to have clear indicators / descriptions for which data is visible for which groups of people. E.g. it would be helpful at the signup process to be informed that the full name is visible to all other volunteers.