e_tizen_testcase: Added eventItem class for containing result of event.

e_tizen_testcase: Added eventItem class for containing result of event.

Added "eventItem" class is result of waitEvent method and it's for store
result of event.
TC developer can inherit eventItem to make custom result.

Changes
- Added eventItem class.
- waitEvent returns shared pointer of eventItem instead of Eina_Bool.
- legacy insertEventQueue creates eventItem and enqueue them to event
queue.
- new overloaded insertEventQueue(eventItem).
- existing testcases are changed using eventItem.

Change-Id: Ic9b65d2a3e958a0619136bf8e85a175cbfacbe01