[Editor] Fix orbit editor camera stutter

sources/editor/Xenko.Assets.Presentation/AssetEditors/EntityHierarchyEditor/Game/EditorGameEntityCameraService.cs

@@ -269,6 +269,8 @@ protected void UpdateCameraBase(ref float yaw, ref float pitch, ref Vector3 posi
                 yaw -= 1.333f * Game.Input.MouseDelta.X * rotationSpeed; // we want to rotate faster Horizontally and Vertically
                 if (input.isRotating || input.isOrbiting)
                     pitch = MathUtil.Clamp(pitch - Game.Input.MouseDelta.Y * rotationSpeed, -MathUtil.PiOverTwo, MathUtil.PiOverTwo);
+                // Yaw & Pitch modified, update quaternion rotation
+                rotation = Quaternion.RotationYawPitchRoll(yaw, pitch, 0);
             }
 
             // Forward/backward