CERN Access: Create a reminder with the link to the personal data form

[mic4ael]

Create a reminder which would remind people of the requirement to fill in the personal data form in order to get the access to the CERN site.

[pferreir]

In the case where someone tries to "Grant access" a second time to one or more participants, we should also show a warning saying that "X e-mails were not sent" and explaining that if they want we can send a reminder to those.