Blender Git Loki

Fix possible crash when blending poses

I did some casting hack to return an `AssetHandle` from a
`FileDirEntry`. But this doesn't actually work.

What I added now isn't something I'm happy with either, but it will have
to do for now. Basically we request an `AssetHandle`, which the Asset
Browser doesn't actually store, since it's just a wrapper around the
Asset Browser's `FileDirEntry`. So there is no consistent pointer the
editor could return to context queries, and the context needs a pointer
so that it can be passed around as `void *`.

Eventually once we have the planned asset storage design implemented,
the storage would include actual asset handles. So we can pass around
consistent pointers to them then.