feat: implement MeshLoader

This loader abstracts mesh loading logic into a series of individual file handlers. Each handler is chosen based on the extension of the file to be loaded.

src/loaders/gltf_loader.rs

@@ -0,0 +1,11 @@
+use std::path::Path;
+use anyhow::Result;
+use crate::loaders::mesh_loader::{MeshFileLoader, MeshInfo};
+
+pub struct GltfLoader;
+
+impl MeshFileLoader for GltfLoader {
+    fn load_mesh(&self, path: &Path) -> Result<MeshInfo> {
+        todo!()
+    }
+}