Investigate Better Calendar Invite Integration with Other Calendar Providers

[wrdhub]

Issue:
When someone creates an event on a non-Tuta Calendar and invites a Tuta address, the way we respond with attendee status does not update the attendee status.

Main platforms to check: iCloud Calendar, Google Calendar, Outlook, and Proton Calendar.

Questions:
Why isn't the response updating the attendee status?
Is there something that we can change to make this work?
Are these changes practical and in line with our security/privacy ideals?
How are responses sent from other platforms? Do our events get updated with the attendee status?

[wrdhub]

#6006 Has some information about this in regards to Outlook