Core/Maps: Don't load vmaps/mmaps if disabled in configs

Don't try to load vmaps/mmaps if they are disabled in the configs.
Fixes #12392
Core/Wintergrasp: Spawn npcs only after initial map configs have been set

Spawn BATTLEFIELD_WG_NPC_STALKER only after the MapID has been set otherwise it will try to spawn it on map 0
Merge branch 'master' of https://github.com/TrinityCore/TrinityCore