Improve python library, add LLGLTF asset parser, Add tests

lib/classes/LLGLTFMaterialData.ts

@@ -0,0 +1,28 @@
+export interface LLGLTFMaterialData
+{
+    asset: {
+        version: string;
+    };
+    images: {
+        uri: string;
+    }[];
+    materials: {
+        normalTexture: {
+            index: number
+        },
+        occlusionTexture: {
+            index: number;
+        },
+        pbrMetallicRoughness: {
+            baseColorTexture: {
+                index: number
+            },
+            metallicRoughnessTexture: {
+                index: number
+            }
+        }
+    }[];
+    textures: {
+        source: number
+    }[];
+}