Message window to send reminders: allow the option to set the replyTo by the user

[melisabok]

I think this could be a workaround for ACs sending reminders to reviewers where they can not reply to them directly.

We could show a checkbox in the message window where the user can check if they want to add their email address in the replyto.

This was discussed here: https://twitter.com/yuvalmarton/status/1748381060092903660

Thoughts? @haroldrubio @enrubio @zbialecki @xkopenreview @celestemartinez

[zbialecki]

I like that idea for venues where reviewers are allowed to see the identity of the ACs. I don't think we'd want to allow it if ACs are meant to be anonymous though.