Add memory support for file_io

[Xuanwo]

          We can use an in-memory filesystem by default, eliminating the need to change the environment. 

I will build one for file_io.

Originally posted by @Xuanwo in #475 (comment)

[sdd]

I have a local branch where I've modified FileIO to add an OpenDAL Layer that does in-memory caching of the underlying files using the moka crate. I can share the details if you think it might be helpful

[Xuanwo]

That's nice! Please share it to me ❤️

By the way, opendal has native support of moka and mini_moka, maybe also useful for caching.