fix node invalid pointer

[T-rvw]

Fix #234 .
Instead of passing pointers, it is more safe to pass ObjectID.

Test result after fix:

FBXSDK Version : 7, 7, 0
FBXFile Version : 7, 4, 0

SceneDatabase :
        Name : G:\ArtAssets\TestAssets\BadCases\walk_from_blender\walk_from_blender.fbx
        AABB :
                Min : (x = -95.136635, y = -0.427658, z = -20.716028)
                Max : (x = 95.095535, y = 200.076752, z = 26.151720)
        AxisSystem :
                Handedness : LeftHandSystem
                UpAxis : (x = 0.000000, y = 1.000000, z = 0.000000)
                FrontAxis : (x = 1.000000, y = 0.000000, z = 0.000000)
        UnitSystem :
                Unit : CenterMeter
        Node count : 2
        Mesh count : 1
        Morph count : 0
        Material count : 1
        Texture count : 2
        Camera count : 0
        Light count : 0
        Bone count : 0
        Animation count : 0
        Track count : 0

[Node 0] ParentID = 4294967295, Name = RootNode
        Translation : (x = 0.000000, y = 0.000000, z = 0.000000)
        Rotation : (w = 1.000000, x = 0.000000, y = 0.000000, z = 0.000000)
        Scale : (x = 1.000000, y = 1.000000, z = 1.000000)
[Node 1] ParentID = 4294967295, Name = Armature
        Translation : (x = 0.000000, y = 0.000000, z = 0.000000)
        Rotation : (w = 1.000000, x = -0.000000, y = 0.000000, z = 0.000000)
        Scale : (x = 1.000000, y = 1.000000, z = 1.000000)

[Mesh 0] Name = Akai
        VertexCount = 31158, TriangleCount = 10386
        [Associated Material 0]

[MaterialID 0] Name = Akai_MAT
        Metallic = 0.100000
        Roughness = 0.900000
        [Associated Texture 0] Type = BaseColor
                Path = C:\Users\V\Desktop\model\TestAssets-main\Downloads\Catwalk Walk Turn 180 Tight.fbm\akai_diffuse.png
                UVScale : (x = 1.000000, y = 1.000000)
                UVOffset : (x = 0.000000, y = 0.000000)
        [Associated Texture 1] Type = Normal
                Path = C:\Users\V\Desktop\model\zachary\Dropbox (Adobe)\Mixamo\Characters\Akai E Espiritu\akai_e_espiritu_20210811.fbm\akai_normal.png
                UVScale : (x = 1.000000, y = 1.000000)
                UVOffset : (x = 0.000000, y = 0.000000)
        [Associated Mesh 0] Akai

[Texture 0] Type = BaseColor
        Name = base_color_texture
        Path = C:\Users\V\Desktop\model\TestAssets-main\Downloads\Catwalk Walk Turn 180 Tight.fbm\akai_diffuse.png
        UVMapMode = (Wrap, Wrap)
[Texture 1] Type = Normal
        Name = normalmap_texture
        Path = C:\Users\V\Desktop\model\zachary\Dropbox (Adobe)\Mixamo\Characters\Akai E Espiritu\akai_e_espiritu_20210811.fbm\akai_normal.png
        UVMapMode = (Wrap, Wrap)

AssetPipeline costs 0.566786 seconds