Add IO-capable TakePartition struct

[oldgalileo]

This PR supports using a "taken" Partition (modeled after std::io::Take) to work with all the normal I/O Read operations, and allows it to work seamlessly with std::io::copy(&mut taken_partition, write_impl)

[oldgalileo]

Mistakenly opened this as a full PR rather than a draft PR.

It would be great to move forward with this as though it were a draft. Beyond the lack of 1.46.0 guarantees (maybe this could be batched into the next major release with breaking changes being to loosen Rust toolchain guarantees), the naming and structure of this was made as an MVP.

[soerenmeier]

Feel free to reopen and rebase if you're still interested.