Update ESI email reminders so a user with multiple projects only gets a single email

[tzumainn]

We use lease-email.py to send up a variety of reminder emails:

https://github.com/CCI-MOC/esi-pilot/tree/main/scripts

These are currently sent out through a cronjob set up on the undercloud:

0 0 * * 1 /home/stack/esi-pilot/scripts/esi-email.sh /home/stack/esi-pilot/scripts/email-reminder.json
59 23 * * * /home/stack/esi-pilot/scripts/esi-email.sh /home/stack/esi-pilot/scripts/email-expiring.json