refactor: create separate package for test suite

[ctrlc03]

Description

Refactor the test suite by moving to own package

Related issue(s)

re #2141

Confirmation

[!IMPORTANT] We do not accept minor grammatical fixes (e.g., correcting typos, rewording sentences) unless they significantly improve clarity in technical documentation. These contributions, while appreciated, are not a priority for merging. If there is a grammatical error feel free to message the team.

• [x] I have read and understand MACI's contributor guidelines and code of conduct.
• [x] I ran and verified that all tests pass according to MACI's testing guide.