Core/Spells: Remove spell range increase when caster or target move backwards

Port From (https://github.com/TrinityCore/TrinityCore/commit/f19e1a271618a35515512ce2a64330f21133616c)

Source/Game/Spells/Spell.cs

@@ -6557,6 +6557,12 @@ namespace Game.Spells
             return SpellCastResult.SpellCastOk;
         }
 
+        public static bool CanIncreaseRangeByMovement(Unit unit)
+        {
+            // forward running only
+            return unit.HasUnitMovementFlag(MovementFlag.Forward | MovementFlag.StrafeLeft | MovementFlag.StrafeRight | MovementFlag.Falling) && !unit.IsWalking();
+        }
+
         (float minRange, float maxRange) GetMinMaxRange(bool strict)
         {
             float rangeMod = 0.0f;
@@ -6598,7 +6604,7 @@ namespace Game.Spells
                     }
                 }
 
-                if (target != null && unitCaster != null && unitCaster.IsMoving() && target.IsMoving() && !unitCaster.IsWalking() && !target.IsWalking() &&
+                if (target != null && unitCaster != null && CanIncreaseRangeByMovement(target) && CanIncreaseRangeByMovement(unitCaster) &&
                     (m_spellInfo.RangeEntry.HasFlag(SpellRangeFlag.Melee) || target.IsPlayer()))
                     rangeMod += 8.0f / 3.0f;
             }

Source/Game/Spells/SpellInfo.cs

@@ -4275,7 +4275,7 @@ namespace Game.Spells
                     modOwner.ApplySpellMod(_spellInfo, SpellModOp.Radius, ref radius, spell);
 
                 if (!_spellInfo.HasAttribute(SpellAttr9.NoMovementRadiusBonus))
-                    if (casterUnit != null && casterUnit.IsMoving() && !casterUnit.IsWalking())
+                    if (casterUnit != null && Spell.CanIncreaseRangeByMovement(casterUnit))
                         radius += 2.0f;
             }