Core/Movement: require a minimum wander_distance value of 0.1 and check the path length of generated random movement

this serves as a means to reduce the console spam caused by failed spline validation
Port From (https://github.com/TrinityCore/TrinityCore/commit/fb3e6737da7795be651d36ce7493c07c7ecbdfeb)

Source/Game/Globals/ObjectManager.cs

@@ -3545,6 +3545,11 @@ namespace Game
                     Log.outError(LogFilter.Sql, "Table `creature` have creature (GUID: {0} Entry: {1}) with `wander_distance`< 0, set to 0.", guid, data.Id);
                     data.WanderDistance = 0.0f;
                 }
+                else if (data.WanderDistance > 0.0f && data.WanderDistance < 0.1f)
+                {
+                    Log.outError(LogFilter.Sql, $"Table `creature` has creature (GUID: {guid} Entry: {data.Id}) with `wander_distance` below the allowed minimum distance of 0.1, set to 0.");
+                    data.WanderDistance = 0.0f;
+                }
                 else if (data.movementType == (byte)MovementGeneratorType.Random)
                 {
                     if (MathFunctions.fuzzyEq(data.WanderDistance, 0.0f))

Source/Game/Movement/Generators/RandomMovementGenerator.cs

@@ -153,8 +153,8 @@ namespace Game.Movement
             }
 
             Position position = new(_reference);
-            float distance = RandomHelper.FRand(0.0f, _wanderDistance);
-            float angle = RandomHelper.FRand(0.0f, MathF.PI * 2.0f);
+            float distance = _wanderDistance > 0.1f ? RandomHelper.FRand(0.1f, _wanderDistance) : _wanderDistance;
+            float angle = RandomHelper.FRand(0.0f, MathF.PI * 2);
             owner.MovePositionToFirstCollision(position, distance, angle);
 
             // Check if the destination is in LOS
@@ -179,6 +179,13 @@ namespace Game.Movement
                 return;
             }
 
+            if (_path.GetPathLength() < 0.1f)
+            {
+                // the path is too short for the spline system to be accepted. Let's try again soon.
+                _timer.Reset(500);
+                return;
+            }
+
             RemoveFlag(MovementGeneratorFlags.Transitory | MovementGeneratorFlags.TimedPaused);
 
             owner.AddUnitState(UnitState.RoamingMove);