Core: NPC Interaction change for unfriendly reputation.

For units with unfriendly reputation, check using the normal reaction function, instead of reading faction directly.

This allows specific buffs that alter creature reaction to work on the player, this allowing players to complete quests.

Closes #13629

src/server/game/Entities/Player/Player.cpp

@@ -2765,17 +2765,10 @@ Creature* Player::GetNPCIfCanInteractWith(ObjectGuid guid, uint32 npcflagmask)
     if (creature->GetCharmerGUID())
         return NULL;
 
-    // not enemy
-    if (creature->IsHostileTo(this))
+    // not unfriendly/hostile
+    if (creature->GetReactionTo(this) <= REP_UNFRIENDLY)
         return NULL;
 
-    // not unfriendly
-    if (FactionTemplateEntry const* factionTemplate = sFactionTemplateStore.LookupEntry(creature->getFaction()))
-        if (factionTemplate->faction)
-            if (FactionEntry const* faction = sFactionStore.LookupEntry(factionTemplate->faction))
-                if (faction->reputationListID >= 0 && GetReputationMgr().GetRank(faction) <= REP_UNFRIENDLY)
-                    return NULL;
-
     // not too far
     if (!creature->IsWithinDistInMap(this, INTERACTION_DISTANCE))
         return NULL;