Core/Vehicles: Fix a crash in VehicleJoinEvent::Execute

Crash would happen if multiple events were scheduled for the same seat.
Fixes #9255
Core/Vehicles: Make RemovePendingEventsForSeat iterating crashsafe
Core/Vehicles: Really make RemovePendingEventsForSeat iterating crash safe
DB/Gameobject: Removed transport gameobject
SQL: Fix "No newline at end of file" in 194cc54f08d8b42c8c49d756e14273d917e1fcf2
Core/RBAC: Fix mem leak
Core/Calendar: Fix mem leak and minor cosmetic changes
Core/Vehicles: Fixed crash in RemovePendingEventsForSeat - changed _pendingJoinEvents container from deque to list as deque invalidates all iterators pointing to the container (including .end()) when performing erase
DB/Trigger: Fixed instance exit of the Culling of Stratholme
Core/Vehicles: Fixed a crash that happened if someone called ExitVehicle during seat changing
Core/Movement: Do not attempt to pathfind for stop/turn movement
Core/Summons: Implement summon groups system to be able to summon multiple NPCs at once without need of hardcoding the positions. Almost all hardcoded positions can now be moved to DB.

Thx to @Shauren for his help.