Core/Misc: Moved Position to its own file

(cherry picked from commit 48ee1f003347910a48183f768501c1080fc40269)

Conflicts:
	src/server/game/Entities/Object/Object.cpp
	src/server/game/Entities/Object/Object.h
	src/server/game/Spells/Spell.cpp

src/server/game/Entities/Unit/Unit.cpp

@@ -390,7 +390,7 @@ void Unit::UpdateSplinePosition()
         pos.m_positionX = loc.x;
         pos.m_positionY = loc.y;
         pos.m_positionZ = loc.z;
-        pos.m_orientation = loc.orientation;
+        pos.SetOrientation(loc.orientation);
 
         if (TransportBase* transport = GetDirectTransport())
             transport->CalculatePassengerPosition(loc.x, loc.y, loc.z, &loc.orientation);