fixed exception handler and moved to common library

.../java/cz/muni/pa165/car/service/DriverManagerService.java

...uni/pa165/common_library/exception/DatabaseException.java

.../java/cz/muni/pa165/common_library/exception/ExError.java

...5/common_library/exception/ResourceNotFoundException.java

.../pa165/common_library/exception/RestExceptionHandler.java

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

race/pom.xml

race/src/main/java/cz/muni/pa165/race/App.java

...src/main/java/cz/muni/pa165/race/service/RaceService.java

...c/main/java/cz/muni/pa165/race/service/SeasonService.java

race/src/main/resources/application.yml