BVH animation loading / retargeting (#25)

This PR adds support for BVH animation files, with a custom animation
player and retargeting solution for our Blender Rigify-based skeletal
meshes.

---------

Co-authored-by: Brooks Palin <brookspalin710@gmail.com>

studio/src/main.rs

@@ -4,7 +4,7 @@ use studio::{StudioMode, ViewportSize};
 fn main() {
     // Edit the arguments here to change the default startup scene or skybox
     let mut app = studio::start_internal(
-        "sample-room",
+        "base-human-female",
         "gum_trees_4k",
         "", // ignored for non-WASM
         "Storyteller Studio",