Core/Position: Refactor GetAngle -> GetAbsoluteAngle because code clarity is good.

Port From (https://github.com/TrinityCore/TrinityCore/commit/bc89e1cdb0da10e53cc9fa4a97565c05bb4c052e)

Source/Game/Spells/Spell.cs

@@ -8332,25 +8332,22 @@ namespace Game.Spells
 
     public class WorldObjectSpellLineTargetCheck : WorldObjectSpellAreaTargetCheck
     {
-        Position _srcPosition;
-        Position _dstPosition;
+        Position _position;
         float _lineWidth;
 
         public WorldObjectSpellLineTargetCheck(Position srcPosition, Position dstPosition, float lineWidth, float range, WorldObject caster, SpellInfo spellInfo, SpellTargetCheckTypes selectionType, List<Condition> condList, SpellTargetObjectTypes objectType)
             : base(range, caster, caster, caster, spellInfo, selectionType, condList, objectType)
         {
-            _srcPosition = srcPosition;
-            _dstPosition = dstPosition;
+            _position = srcPosition;
             _lineWidth = lineWidth;
+
+            if (dstPosition != null && srcPosition != dstPosition)
+                _position.SetOrientation(srcPosition.GetAbsoluteAngle(dstPosition));
         }
 
         public override bool Invoke(WorldObject target)
         {
-            float angle = _caster.GetOrientation();
-            if (_srcPosition != _dstPosition)
-                angle = _srcPosition.GetAngle(_dstPosition);
-
-            if (!_caster.HasInLine(target, target.GetCombatReach(), _lineWidth, angle))
+            if (!_position.HasInLine(target, target.GetCombatReach(), _lineWidth))
                 return false;
 
             return base.Invoke(target);

Source/Game/Spells/SpellEffects.cs

@@ -1927,7 +1927,7 @@ namespace Game.Spells
                 unitTarget.GetMotionMaster().MoveDistract((uint)(damage * Time.InMilliseconds));
 
             unitTarget.StopMoving();
-            unitTarget.SetFacingTo(unitTarget.GetAngle(destTarget));
+            unitTarget.SetFacingTo(unitTarget.GetAbsoluteAngle(destTarget));
         }
 
         [SpellEffectHandler(SpellEffectName.Pickpocket)]
@@ -4863,7 +4863,7 @@ namespace Game.Spells
                     summon.SetFaction(unitCaster.GetFaction());
 
                 if (summon.HasUnitTypeMask(UnitTypeMask.Minion) && m_targets.HasDst())
-                    ((Minion)summon).SetFollowAngle(unitCaster.GetAngle(summon.GetPosition()));
+                    ((Minion)summon).SetFollowAngle(unitCaster.GetAbsoluteAngle(summon.GetPosition()));
 
                 if (summon.GetEntry() == 27893)
                 {