Implement exponential backoff after receiving 429 error from Google Calendar API

[tyler-dane]

Feature Description

This feature should only be addressed as part of #504 if we actually run into a 429 error. If not, we can delay this for another time.

Use Case

By waiting before making subsequent requests after receiving a 429, we can allow the seed command to work without requiring the user to do anything different.

Additional Context

One way to implement this as part of the seed CLI would be to return after a 429 error, but notify the user that we are processing the remaining events in the background. That way, the user can start using their new calendar events immediately without having to wait for all the remaining events to be created.

Consider using the exponential-backoff package. See #581 for an example of its usage.

https://developers.google.com/workspace/calendar/api/guides/errors#429_too_many_requests

https://developers.google.com/workspace/calendar/api/guides/errors#exponential-backoff

https://cloud.google.com/storage/docs/retry-strategy