Support more options for asset management

[dementrock]

Right now seems like if the file does not exist locally, it defaults to looking up on huggingface. This may not work for commercial users. Should allow more explicit scheme (e.g. perhaps huggingface should use hf://...) and ideally can support other options, e.g. s3, git (including git lfs).

[Fisher-Wang]

Thank you Rocky! Let me investigate alternatives for commercial users