Persist Google Calendar Selected State

[KevinWu098]

When we fetch events from google calendar, we render it on the availability grid on the personal view. The shape of the data returned should include the specific calendars, as well as their settings

We would like to, on the overlay, allow users to selectively toggle on/off specific calendars. To do this, we will need to persist state of the user's calendars in our database.

There are a few considerations. When a user syncs with Google Calendar, we should:

1. If we have never "synced" this user before, we should store all of their google calendar IDs and whether each calendar is enabled or not
2. If the user has been "synced" before, meaning some calendars are in the DB, we should, for the selected state, prioritize ZotMeet's enabled setting. Which is to say, if the enabled setting is on in GC, but off in ZM, we should prefer ZM
3. If a calendar is no longer on google calendar, we should also soft delete it from zotmeet, marking it as archived

We do not want to store the actual calendar events itself, or any data relating to the calendar aside from its unique identifier.

On the UI, we'll want to render a set of toggles on the side. You can reference Timeful's implementation for inspiration.