[CAL-3552] The reschedule option on a booking should only appear before an event start time

[shirazdole]

We've had issues from customers where people were rescheduling events that they didn't show up for days, weeks or months previous.

The definition of "reschedule" is to “change the time of a planned event.” The default behaviour should be: no reschedule after an event start time.

We may make a completely separate feature request to allow other reschedule options like…

• Flexible: allow reschedule within a grace period of X mins after start time
• Strict: only allow reschedule up to X hours before start time

_{From SyncLinear.com | CAL-3552}