Core/Spells: Implemented SPELL_ATTR9_TARGET_MUST_BE_GROUNDED

Port From (https://github.com/TrinityCore/TrinityCore/commit/dd61ba2844fc96b3344183fe0b05ce65985fa8be)

Source/Framework/Constants/Spells/SpellConst.cs

@@ -1976,7 +1976,7 @@ namespace Framework.Constants
         DoNotAddToUnlearnList = 0x80, //  NYI - unlearn list not maintained SMSG_SEND_UNLEARN_SPELLS always empty // Do Not Add to Unlearn List
         CooldownIgnoresRangedWeapon = 0x100, // Cooldown Ignores Ranged Weapon
         NotInArena = 0x200, // 9 Not In Arena
-        Unk10 = 0x400, // 10
+        TargetMustBeGrounded = 0x400, // Target Must Be Grounded
         Unk11 = 0x800, // 11
         Unk12 = 0x1000, // 12
         Slam = 0x2000, // 13

Source/Game/Spells/SpellInfo.cs

@@ -1079,6 +1079,11 @@ namespace Game.Spells
                 if (HasAttribute(SpellAttr3.NotOnAoeImmune))
                     if (unitTarget.GetSpellOtherImmunityMask().HasFlag(SpellOtherImmunity.AoETarget))
                         return SpellCastResult.BadTargets;
+
+                if (HasAttribute(SpellAttr9.TargetMustBeGrounded) &&
+                    (unitTarget.HasUnitMovementFlag(MovementFlag.Falling | MovementFlag.Swimming | MovementFlag.Flying | MovementFlag.Hover) ||
+                    unitTarget.HasExtraUnitMovementFlag2(MovementFlags3.AdvFlying)))
+                    return SpellCastResult.TargetNotGrounded;
             }
             // corpse specific target checks
             else if (target.IsTypeId(TypeId.Corpse))