Fix BoundedInt Sub libfunc (#1465)

* Add tests for bounded int sub

* Change sub implementation

* Uncomment test

* Do a safer parsing

* Add more comments

* Refactor of tests

* Refactor tests

* Improve docs

* Remove asserts

* Fix clippy

* Refactor of tests names

* Update src/libfuncs/bounded_int.rs

Co-authored-by: Julian Gonzalez Calderon <gonzalezcalderonjulian@gmail.com>

* Update src/libfuncs/bounded_int.rs

Co-authored-by: Gabriel Bosio <38794644+gabrielbosio@users.noreply.github.com>

---------

Co-authored-by: Julian Gonzalez Calderon <gonzalezcalderonjulian@gmail.com>
Co-authored-by: Gabriel Bosio <38794644+gabrielbosio@users.noreply.github.com>

Author: 3 people