(T25) Refactoring: replace PersoRequest::get_ship by Ship::get

Summary:
Reefactor PersoRequest get ship code

Allowing Ship::get($data) to accept ship id (1) or code (S00001)

Test Plan: a manual API auth test

Reviewers: dereckson

Reviewed By: dereckson

Maniphest Tasks: T25

Differential Revision: http://code.zed.dereckson.be/D2