[CAL-2801] Overlay my calendar v2

[ciaranha]

We recently added a v1 of "Overlay my calendar". This currently allows you to access this feature if you have a Cal.com account.

For v2 we need to

1. Add other providers
   • Sign in with Google
   • Sign in with Microsoft
   • Any others?
2. Replace "Busy" events with the actual info from the calendar it is pulling from*
3. Overlay should be default on for all logged in users
4. For logged-in users it should check for conflicts of the connected calendars that are toggled for conflict checking in calendar settings + cal.com bookings

**the getBusyTimes doesn't currently pull in any calendar titles as it is mainly called in a public endpoint. We will need to use getServerSide session and make changes to ALL calendar services to pull this info in.

View in Figma

_{From SyncLinear.com | CAL-2801}

[siddanth-6365]

can i pick this?

[DhirajMohata]

can i pick this?

[TyceHerrman]

@ciaranha any update on this? This is the one feature that's keeping me from switching from savvycal. Obviously lots to work on and just n of 1 here, but any updates on when we might see this would be great ✌️