[Koha] Capturing a "consent" field for new patrons

[Chris Brown]

Gentle Reader,

We need to capture an email "consent" field when we add new patrons to
Koha. Currently my solution is to have staff type "yes" or "no" into the
borrowernotes field  but what I would really like is to have "yes" and "no"
radio buttons, or failing that a drop-down with "yes" and "no" as the only
options. And it would be really good if the field was labelled "email
consent" on the patron entry form.

Any suggestions gratefully received!

Best Regards,

Chris Brown