Merge branch 'rnou/216-increase-testing-coverage' into 'master'

Resolve "increase testing coverage"

This MR increases testing coverage significantly by including additional tests and implementing basic syscall testing.

It also fixes the following issues:
* Include `<array>` to compile with GCC 12.1
* Solved SIGSEV in fchdir (When debug is enabled)

Closes #216

See merge request !141