Expose `worksheet_range_ref` variant for the Rust API?

[temaxuck]

Since this library provides a way to load data "eagerly" for the Python API using calamine's worksheet_range_ref, shouldn't it also provide similar method for the Rust API?

[temaxuck]

I'm willing to implement this feature if it aligns with the design of the API.

[lukapeschke]

It should be possible, but non-trivial: Since PyO3 does not allow to expose lifetimes in the struct, we'd need a wrapper type, and the Python ExcelSheet type would have to be different from the Rust one