Describe new EventSingleClickEvent and EventDoubleClickEvent events for FullCalendar

[Flaurite]

Description

Origin: jmix-framework/jmix#4721

Please note that feature will be available in 2.7.2+

It is need to describe:

1. EventSingleClickEvent
2. EventDoubleClickEvent
3. New property in FullCalendar component - eventSingleClickThreshold
4. New property in MouseEventDetails - clickCount.