refactor(Core): rename namespaces and macros to acore (#2454)

src/server/game/Combat/ThreatManager.cpp

@@ -279,7 +279,7 @@ void ThreatContainer::modifyThreatPercent(Unit* victim, int32 percent)
 void ThreatContainer::update()
 {
     if (iDirty && iThreatList.size() > 1)
-        iThreatList.sort(Trinity::ThreatOrderPred());
+        iThreatList.sort(acore::ThreatOrderPred());
 
     iDirty = false;
 }

src/server/game/Combat/ThreatManager.h

@@ -259,7 +259,7 @@ class ThreatManager
 
 //=================================================
 
-namespace Trinity
+namespace acore
 {
     // Binary predicate for sorting HostileReferences based on threat value
     class ThreatOrderPred