Added Dto validation + changed characteristics handling

common_library/pom.xml

.../java/cz/muni/pa165/common_library/dtos/DriverAddDto.java

...a/cz/muni/pa165/common_library/dtos/DriverInsightDto.java

...va/cz/muni/pa165/common_library/dtos/DriverUpdateDto.java

...a/cz/muni/pa165/common_library/racecomponents/Driver.java

...65/common_library/validator/CharacteristicsValidator.java

.../pa165/common_library/validator/ValidCharacteristics.java

...c/main/java/cz/muni/pa165/driver/mapper/DriverMapper.java

...in/java/cz/muni/pa165/driver/mapper/DriverMapperImpl.java

...main/java/cz/muni/pa165/driver/rest/DriverController.java

...main/java/cz/muni/pa165/driver/service/DriverService.java

.../java/cz/muni/pa165/driver/service/DriverServiceImpl.java