[CAL-3581] [Api][v2] getEventType endpoint should be client agnostic

[ThyMinimalDev]

• remove getUserEventTypeForAtom
• get a standard event-type entity

formatting should be done inside of the hooks

• useGetEventTypeById

_{From SyncLinear.com | CAL-3581}

[ThyMinimalDev]

@lauris @ebruinsma @rajiv @keithwillcode

[martinsione]

Is this being worked on and also is this open to community contributions? I'd love to contribute