Use Gravatar's for operator icons

[mihok]

Problem description:

Currently we have static image placeholders used for avatar images on operators (that are not sent out to the client)

Suggested solution:

Support gravatar images for avatars as a band-aid solution until/if we support custom avatar images. This will require an email field in the settings/config.json and to send this email along to clients as well.

[subhan-f]

Hello! I’d love to take this on. The plan would be to add an email field to the settings, then use that email to generate a Gravatar URL for the operator icon, and send the email to the client as described. Please assign it to me if that works. I’ve read the contributing guidelines. /assign