[Feature request] Public API for users

[urmade]

Is your feature request related to a problem? Please describe.
To make our community more transparent it would be great to have a public API where our members can be fetched (anonymously or with some details). This could be embedded in our website.

Describe the solution you'd like
API endpoints that return:
Count of all members
All members
All members of a specific hub / campus
All campus (with longitude / latitude)

Members should have an option to opt into being displayed publicly on the website. For that we need a new meta-attribute for users through MS Graph extensions.

If a user has opted into being public, the API should return the users name and profile picture. By default, the studies and the date they joined the campus community should be returned by the API.