Add recursive factorial implementation with tests (#7178)

* Add recursive factorial implementation with tests

* [STYLE] Apply clang-format

* Move recursive factorial to recursion package and remove duplicate

* Move recursive factorial to recursion package and remove duplicate

* Apply clang-format to factorial recursion tests

* Apply clang-format to factorial recursion tests

---------

Co-authored-by: Koushik Sai <nyamathabadkoushik@gmail.com>
Co-authored-by: Deniz Altunkapan <deniz.altunkapan@outlook.com>