* `game_event_pool` dropped and related in momory data generated
based by another pool tables content.
* Pool work with spawed at event and despawned at event object now different.
- If object listed in `game_event_*` as spawned at event start and it's part of some pool
then all other pool object must be listed as spawned with this event start, and more,
if pool has mother pool, then all mother pool members must have objects spawned at this
event start. More short: all object of some top (not have mother pool) mitbe or listed for some event start spawn,
or not listed for any event start spawn.
- If object listed in `game_event_*` as DEspawned at event start and it's part of some pool
then nothing special required for other pool objects. Event systemwil command to pool system exclude for spawning and despawn referenced
object until event end.
* Many checks has been added at event/pool data loading.
* Changes fix crashes related to event/pool common work.
Thanks to NoFantasy for help in research original problems and ways for improve code.
* src/game/GameEvent.* renamed to src/game/GameEventMgr.* for consistence
* `game_event` now have new `holiday` field for store client side holiday id associated with game event
* Added new enum HolidayIds with existed at this moment holiday ids.
* New function "bool IsHolidayActive(HolidayIds id)" added accessabel from scripts for active holidays check.
