Add isSelected property to EventModel.

[striker]

Add isSelected property to EventModel in Scheduler.
It will help to detect selected events on scheduler.

You can implement additionaly some methods like event.select(), eventStore.getSelected()

[johan.isaksson]

HI,

The event itself lives on the datalayer and is not aware of if it is selected or not. You can instead find out if an event is selected using functionality on Scheduler. For example:

https://bryntum.com/docs/scheduler/#Scheduler/view/Scheduler#function-isEventSelected
https://bryntum.com/docs/scheduler/#Scheduler/view/Scheduler#property-selectedEvents