Ajout de fonctionalités pour Student au backend

.gitattributes

.gitignore

.mvn/wrapper/maven-wrapper.properties

mvnw

mvnw.cmd

pom.xml

...m/example/gestionstagesbackend/Config/SecurityConfig.java

...gestionstagesbackend/GestionStagesBackendApplication.java

...gestionstagesbackend/controllers/CandidacyController.java

...estionstagesbackend/controllers/EnterpriseController.java

...e/gestionstagesbackend/controllers/StudentController.java

...estionstagesbackend/enums/AcceptedCandidacyStateKind.java

...ple/gestionstagesbackend/enums/CandidacyRequestState.java

...ava/com/example/gestionstagesbackend/model/Candidacy.java

...va/com/example/gestionstagesbackend/model/Enterprise.java

...in/java/com/example/gestionstagesbackend/model/Stage.java

.../java/com/example/gestionstagesbackend/model/Student.java

...om/example/gestionstagesbackend/model/UnivSupervisor.java

...estionstagesbackend/repositories/CandidacyRepository.java

...stionstagesbackend/repositories/EnterpriseRepository.java