Utility classes to integrate the (Object Store)[https://crates.io/crates/object_store] in an application. This started initially as an effort in (Polars)[https://pola.rs]

BRAINSTORM

Since the Polars implementation relies heavily on (mmap)[https://crates.io/crates/memmap2] our API will be inspired from that crate.

1. Use the mmap interface for the advise operation.
2. Change the polars code to issue advise() before access.
3. Implement the advise on top of object_store in the current crate.

DELIVERY PHASES

1. download
2. cache
3. validated the cache
4. sparse downloads