Refactor demo store to use GitHub artifacts

[chernyadev]

Refactor DemoStore to use GitHub releases from this repo: bigym_data.

Additional changes:

• Added persistent cache for demonstrations created locally from lightweight dataset demos.
• Simplified demo player tools/demo_player by removing redundant functionality.

[Yusufma03]

I'm having this bug when caching the demos.

Traceback (most recent call last):
  File "/Users/xiao/miniconda3/lib/python3.10/multiprocessing/process.py", line 314, in _bootstrap
    self.run()
  File "/Users/xiao/miniconda3/lib/python3.10/multiprocessing/process.py", line 108, in run
    self._target(*self._args, **self._kwargs)
  File "/Users/xiao/work/robobase/robobase/envs/bigym.py", line 184, in _get_demo_fn
    demos = demo_store.get_demos(
  File "/Users/xiao/work/bigym_release/demonstrations/demo_store.py", line 155, in get_demos
    self.cache_demo(demo, frequency)
  File "/Users/xiao/work/bigym_release/demonstrations/demo_store.py", line 81, in cache_demo
    file_path = demo.save(Path(temp_dir) / demo.metadata.filename)
  File "/Users/xiao/work/bigym_release/demonstrations/demo.py", line 285, in save
    save_file(demo_dict, path, self.safetensor_metadata)
  File "/Users/xiao/work/bigym_release/demonstrations/demo.py", line 317, in safetensor_metadata
    return self.metadata.ready_for_safetensors()
  File "/Users/xiao/work/bigym_release/demonstrations/utils.py", line 132, in ready_for_safetensors
    "environment_data": json.dumps(asdict(self.environment_data)),
  File "/Users/xiao/miniconda3/lib/python3.10/json/__init__.py", line 231, in dumps
    return _default_encoder.encode(obj)
  File "/Users/xiao/miniconda3/lib/python3.10/json/encoder.py", line 199, in encode
    chunks = self.iterencode(o, _one_shot=True)
  File "/Users/xiao/miniconda3/lib/python3.10/json/encoder.py", line 257, in iterencode
    return _iterencode(o, 0)
  File "/Users/xiao/miniconda3/lib/python3.10/json/encoder.py", line 179, in default
    raise TypeError(f'Object of type {o.__class__.__name__} '
TypeError: Object of type ListConfig is not JSON serializable

After looking into it, the bug seems to be that in the camera configs, resolution is ListConfig rather than list. I temporarily patched it and pushed to this branch, but I think we need a more elegant fix.

[Yusufma03]

For path of cached demos seem to have the wrong version? Currently mine is 0.9.0, see my path below

/Users/xiao/.bigym/demonstrations/0.9.0

[Yusufma03]

For path of cached demos seem to have the wrong version? Currently mine is 0.9.0, see my path below

/Users/xiao/.bigym/demonstrations/0.9.0

I tested again and this is the only issue left. Otherwise it is good to go!

[chernyadev]

Dataset and BiGym are versioned separately, so it’s intended that demonstrations have v0.9.0.