[CAL-3069] remember last event-type slug when renaming

[PeerRich]

when renaming a slug, it would be nice if the old link still works and redirects

only the previous link, we forget the next one after

i.e.:

cal.com/peer/30min => cal.com/peer/meeting => cal.com/peer/demo = free up /30min, redirect /meeting to /demo

when making a new event, overwrite the redirect

example:

/meeting redirects to /demo

user makes a new /meeting event-type

redirect stops and new /meeting event-type is being used

_CAL-3069

[ngworks1909]

I would like to work on it