ajout des roles a la navbar

src/App.js

src/components/Candidatures/CandidacyForm.jsx

src/components/Candidatures/CandidacyList.jsx

src/components/Candidatures/UpdateCandidacyForm.jsx

src/components/Entreprises/EnterpriseForm.jsx

src/components/Entreprises/EnterpriseList.jsx

src/components/Entreprises/UpdateEnterpriseForm.jsx

src/components/Login.jsx

src/components/Logout.jsx

src/components/Navbar.jsx

src/components/Stages/StageForm.jsx

src/components/Stages/StageList.jsx

src/components/Stages/UpdateStageForm.jsx

src/components/Students/StudentForm.jsx

src/components/Students/StudentList.jsx

src/components/Students/UpdateStudentForm.jsx

src/components/Supervisors/UnivSupervisorForm.jsx

src/components/Supervisors/UnivSupervisorList.jsx

src/components/Supervisors/UpdateUnivSupervisorForm.jsx