Firebase Cloud Functions Email Verification -- 2

## Requirements: We need two cloud functions. The goal is the verify emails: 1. Sending an email with a confirmation link 1. triggered by Firestone onUpdate, when field email_university gets updated 2. The email has to contain a link with a specific token and timestamp 1. The Token + TimeStamp needs to be stored in a separate Firebase collection (name: university_email_verification, fields: token, timestamp, user_id) 2. Verification of the link 1. Triggered by HTTPS request 2. Has to check if the token and timestamp from the link is valid (valid if not older than 1h) 3. Has to set the user (collection users) field email_university_verified to true if 4. After running it should navigate to a failed or success page on our website (use links from section links)