Add CountryRepository

core/src/main/java/cz/muni/fi/pa165/core/data/repository/country/CountryRepository.java

+package cz.muni.fi.pa165.core.data.repository.country;
+
+import cz.muni.fi.pa165.core.data.domain.Country;
+import cz.muni.fi.pa165.core.data.repository.common.BaseRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+import org.springframework.stereotype.Repository;
+
+import java.util.Optional;
+
+@Repository
+public interface CountryRepository extends BaseRepository<Country, Long> {
+
+    @Query("SELECT c FROM Country c WHERE c.name = :name")
+    Optional<Country> findByName(@Param("name") String name);
+}