Introduce Hibernate-Validator

[GeloPakDev]

Add hibernate-validator for our DTOs and models

Provide the validation for REST API input data using @Validated and @Valid annotations

Create custom ResourceNotFoundException - if the required resource cannot be found

Create custom exception handler for:

• unauthorized exception -> message + HTTP 401 or 403

• ConstraintViolationException -> all constraint violations + HTTP 400

• MethodArgumentNotValidaException -> message + HTTP 400

• ResourceNotFoundException -> message + HTTP 404

[kolesroma]

made exception and validator

[kolesroma]

didn't create validation for QuizController cuz I don't have it in current scope. Tried to make a pr from branch origin/create-quiz-controller but that branch contains many other modifications and leads to merge conflict. Im gonna refactor in develop soon

[kolesroma]

gereralized exceptions