Ability to download check in timestamp with attendees data

**Is your feature request related to a problem? Please describe.**
When exporting customer data, it would be useful to be able to include the timestamp of when the customer checked/scanned in so users can analyse check in times to plan for security requirements etc.

**Describe the solution you'd like**
An attentional check box in the export customer data dialogue to include "Checked in date/time"

**Describe alternatives you've considered**
Another option would be to have an "export check in information" on the check in page but I feel the above option if cleaner.

**Additional context**
Perhaps there are other useful fields in the database which are currently not exportable?

Thanks for reading!