Core/Spells: Ignore LoS when spells are cast/triggered by gameobjects

... and this is why you shouldn't use the so called hacks. You will just
 keep adding sh*t on top of more sh*t (like this).
Currently, GO spell casts spawn an invisible WORLD_TRIGGER (npc 12999)
 inside of the gameobject (for certain forms of gameobjects) (and
 this is why the LoS check was failing).
It shouldn't be like that. GOs should be able to cast the spells without
 having to spawn an auxiliary creature.

Fixes "Eye of Acherus" and others

src/server/game/Entities/GameObject/GameObject.cpp

@@ -1674,7 +1674,7 @@ void GameObject::CastSpell(Unit* target, uint32 spellId)
     else
     {
         trigger->setFaction(14);
-        // Set owner guid for target if no owner avalible - needed by trigger auras
+        // Set owner guid for target if no owner available - needed by trigger auras
         // - trigger gets despawned and there's no caster avalible (see AuraEffect::TriggerSpell())
         trigger->CastSpell(target ? target : trigger, spellInfo, true, 0, 0, target ? target->GetGUID() : 0);
     }