Storing Parent Entity Id's in All Child Entities (unitycatalog#38)

* Storing Parent Id's instead of names in all child entities.
* This keeps parent child relationships consistent on parent entity name
updates.
* Added test cases to test out similar scenarios.
* Move all validation (entity not found, entity already existing) under
a single transaction.

### Testing
Ran All Tests by running `build/sbt clean test` and they succeed.

server/src/main/java/io/unitycatalog/server/persist/CatalogRepository.java

@@ -0,0 +1,146 @@
+package io.unitycatalog.server.persist;
+
+import io.unitycatalog.server.exception.BaseException;
+import io.unitycatalog.server.exception.ErrorCode;
+import io.unitycatalog.server.model.CatalogInfo;
+import io.unitycatalog.server.model.ListCatalogsResponse;
+import io.unitycatalog.server.persist.dao.CatalogInfoDAO;
+import io.unitycatalog.server.utils.ValidationUtils;
+import lombok.Getter;
+import org.hibernate.query.Query;
+import io.unitycatalog.server.model.CreateCatalog;
+import io.unitycatalog.server.model.UpdateCatalog;
+import org.hibernate.Session;
+import org.hibernate.SessionFactory;
+import org.hibernate.Transaction;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.Date;
+import java.util.stream.Collectors;
+
+public class CatalogRepository {
+    @Getter
+    private static final CatalogRepository instance = new CatalogRepository();
+    private static final Logger LOGGER = LoggerFactory.getLogger(CatalogRepository.class);
+    private static final SessionFactory sessionFactory = HibernateUtil.getSessionFactory();
+    private CatalogRepository() {}
+
+    public CatalogInfo addCatalog(CreateCatalog createCatalog) {
+        ValidationUtils.validateSqlObjectName(createCatalog.getName());
+        CatalogInfoDAO catalogInfo = new CatalogInfoDAO();
+        catalogInfo.setId(java.util.UUID.randomUUID());
+        catalogInfo.setName(createCatalog.getName());
+        catalogInfo.setComment(createCatalog.getComment());
+        catalogInfo.setCreatedAt(new Date());
+
+        try (Session session = sessionFactory.openSession()) {
+            Transaction tx = session.beginTransaction();
+            try {
+                if (getCatalogDAO(session, createCatalog.getName()) != null) {
+                    throw new BaseException(ErrorCode.ALREADY_EXISTS,
+                            "Catalog already exists: " + createCatalog.getName());
+                }
+                session.persist(catalogInfo);
+                tx.commit();
+                System.out.println("Added catalog: " + catalogInfo.getName());
+                return CatalogInfoDAO.toCatalogInfo(catalogInfo);
+            } catch (Exception e) {
+                tx.rollback();
+                throw e;
+            }
+        }
+    }
+
+    public ListCatalogsResponse listCatalogs() {
+        ListCatalogsResponse response = new ListCatalogsResponse();
+        try (Session session = sessionFactory.openSession()) {
+            session.setDefaultReadOnly(true);
+            Transaction tx = session.beginTransaction();
+            try {
+                response.setCatalogs(session
+                        .createQuery("from CatalogInfoDAO ", CatalogInfoDAO.class).list()
+                        .stream().map(CatalogInfoDAO::toCatalogInfo).collect(Collectors.toList()));
+                tx.commit();
+            } catch (Exception e) {
+                tx.rollback();
+                throw e;
+            }
+            return response;
+        }
+    }
+
+    public CatalogInfo getCatalog(String name) {
+        try (Session session = sessionFactory.openSession()) {
+            session.setDefaultReadOnly(true);
+            Transaction tx = session.beginTransaction();
+            CatalogInfoDAO catalogInfo = null;
+            try {
+                catalogInfo = getCatalogDAO(session, name);
+                tx.commit();
+            } catch (Exception e) {
+                tx.rollback();
+                throw e;
+            }
+            if (catalogInfo == null) {
+                throw new BaseException(ErrorCode.NOT_FOUND, "Catalog not found: " + name);
+            }
+            return CatalogInfoDAO.
+                    toCatalogInfo(getCatalogDAO(session, name));
+        }
+    }
+
+    public CatalogInfoDAO getCatalogDAO(Session session, String name) {
+        Query<CatalogInfoDAO> query = session
+                .createQuery("FROM CatalogInfoDAO WHERE name = :value", CatalogInfoDAO.class);
+        query.setParameter("value", name);
+        query.setMaxResults(1);
+        return query.uniqueResult();
+    }
+
+    public CatalogInfo updateCatalog(String name, UpdateCatalog updateCatalog) {
+        ValidationUtils.validateSqlObjectName(updateCatalog.getNewName());
+        // cna make this just update once we have an identifier that is not the name
+        try (Session session = sessionFactory.openSession()) {
+            Transaction tx = session.beginTransaction();
+            try {
+                CatalogInfoDAO catalogInfo = getCatalogDAO(session, name);
+                if (catalogInfo == null) {
+                    throw new BaseException(ErrorCode.NOT_FOUND, "Catalog not found: " + name);
+                }
+                if (getCatalogDAO(session, updateCatalog.getNewName()) != null) {
+                    throw new BaseException(ErrorCode.ALREADY_EXISTS,
+                            "Catalog already exists: " + updateCatalog.getNewName());
+                }
+                catalogInfo.setName(updateCatalog.getNewName());
+                catalogInfo.setComment(updateCatalog.getComment());
+                catalogInfo.setUpdatedAt(new Date());
+                session.merge(catalogInfo);
+                tx.commit();
+                return CatalogInfoDAO.toCatalogInfo(catalogInfo);
+            } catch (Exception e) {
+                tx.rollback();
+                throw e;
+            }
+        }
+    }
+
+    public void deleteCatalog(String name) {
+        try (Session session = sessionFactory.openSession()) {
+            Transaction tx = session.beginTransaction();
+            try {
+                CatalogInfoDAO catalogInfo = getCatalogDAO(session, name);
+                if (catalogInfo != null) {
+                    session.remove(catalogInfo);
+                    tx.commit();
+                    LOGGER.info("Deleted catalog: {}", catalogInfo.getName());
+                } else {
+                    throw new BaseException(ErrorCode.NOT_FOUND, "Catalog not found: " + name);
+                }
+            } catch (Exception e) {
+                tx.rollback();
+                throw e;
+            }
+        }
+    }
+}