Core/Movement: Ensure land and takeoff animations even if gravity enabled/disabled state is not what spline generator expects

Port From (https://github.com/TrinityCore/TrinityCore/commit/be3ae90dc488894afea8e4cca74d9105558fff53)

Source/Game/Movement/Generators/MovementGenerators.cs

@@ -17,6 +17,12 @@ namespace Game.Movement
         public UnitState BaseUnitState;
         public TaskCompletionSource<MovementStopReason> ScriptResult;
 
+        ~MovementGenerator()
+        {
+            // Ensure script doesn't get stuck waiting for this movement
+            SetScriptResult(MovementStopReason.Interrupted);
+        }
+
         // on top first update
         public virtual void Initialize(Unit owner) { }
 

Source/Game/Movement/MotionMaster.cs

@@ -645,6 +645,8 @@ namespace Game.Movement
             {
                 init.MoveTo(pos, false);
                 init.SetAnimation(AnimTier.Ground, tierTransitionId.GetValueOrDefault(1));
+                init.SetFly(); // ensure smooth animation even if gravity is enabled before calling this function
+                init.SetSmooth();
                 switch (speedSelectionMode)
                 {
                     case MovementWalkRunSpeedSelectionMode.ForceRun:
@@ -669,7 +671,8 @@ namespace Game.Movement
             var initializer = (MoveSplineInit init) =>
             {
                 init.MoveTo(pos, false);
-                init.SetAnimation(AnimTier.Hover, tierTransitionId.GetValueOrDefault(15));
+                init.SetAnimation(AnimTier.Fly, tierTransitionId.GetValueOrDefault(2));
+                init.SetFly(); // ensure smooth animation even if gravity is disabled after calling this function
                 switch (speedSelectionMode)
                 {
                     case MovementWalkRunSpeedSelectionMode.ForceRun:

Source/Game/Movement/MoveSplineInit.cs

@@ -321,7 +321,8 @@ namespace Game.Movement
             args.animTier = new();
             args.animTier.TierTransitionId = tierTransitionId;
             args.animTier.AnimTier = (byte)anim;
-            args.flags.EnableAnimation();
+            if (tierTransitionId == 0)
+                args.flags.EnableAnimation();
         }
 
         public void DisableTransportPathTransformations() { args.TransformForTransport = false; }