implement C++ or rust backend for isoreader

[sebkopf]

to address type safety and speed issues:

• https://www.rcpp.org/
• https://adv-r.hadley.nz/rcpp.html (great resource)
• https://github.com/extendr/extendr
• https://cran.r-project.org/web/packages/rextendr/vignettes/package.html
• https://github.com/r-rust

getting started with rust, e.g.:

https://doc.rust-lang.org/cargo/guide/creating-a-new-project.html
https://web.mit.edu/rust-lang_v1.25/arch/amd64_ubuntu1404/share/doc/rust/html/book/first-edition/crates-and-modules.html

example of a Rust library with python & R wrappers:

• https://github.com/pola-rs/polars (uses apache arrow memory format)
• https://github.com/pola-rs/r-polars (R implementation)
• tidyverse type python bindings for polars: https://github.com/markfairbanks/tidypolars