Create recurring grid events

[tyler-dane]

Feature Description

• You can already create a recurring sidebar event
• Viewing and editing existing recurring grid events were accomplished as part of ✨ Render recurring grid events (readonly) #225 and ✨ Edit recurring events #226
• This story is about creating a new recurring grid event

Acceptance Criteria

• Unit tests added for the creating the correct recurrence rule

Use Case

No response

Additional Context

https://developers.google.com/calendar/api/concepts/events-calendars#recurring_events
https://datatracker.ietf.org/doc/html/rfc5545
https://developers.google.com/calendar/api/guides/recurringevents