WorldSimulation.cpp

- In World::update, inside the for loop with entities, update the player characters every n seconds (in this case, 5 secs)
- charUpdateDb(e) is a placeholder atm

Entity.cpp and .h
- Added a function to check the if the player has a valid DbStoreFlag

To-do and/or wishlists:
- (To confirm with others) Call GameDbSyncContext::performUpdate based on the DbStoreFlag, and put the required data into the structs as parameters
- Modify slashCommand.cpp so that they actually update the database

In GameDbSyncEvents.h, I changed my structs' m_id to uint64_t, since Entity::GetAccountId returns uint64_t as well.
And I tried to make GameDbSyncService closer to WorldSimulation

Minor update attempting to remove Wnarrowing warnings/errors

- In GameDBSyncService.cpp, changed how entity.m_db_store_flags is checked to update things (Well, that was a learning experience on bitwise operations)
- In MapInstance.cpp, added m_sync_service->activate() on MapInstance::start and call m_sync_service->on_update_timer on the same way m_world->update is called