* Fix small bug when registering resource providers.
* Add test cases for OS filesystem fallback with VFS.
* Rewrite LoadModelFromString using a resource provider (now can pass custom VFSs).
PiperOrigin-RevId: 526959705
Change-Id: Iee1773e5584535d868aab6b206d1bf362e600c8a
A resource provider provides a mechanism for MuJoCo to read from filesystems other than the OS filesystem or the Virtual File System (VFS).
PiperOrigin-RevId: 525394983
Change-Id: I077ff5a7e2e76806b48b6defb531280aadc8b169