Adapt to breaking changes to SHOW DATABASES (#3)

SHOW DATABASES has a couple of breaking changes in 5.x
 * role is now simply 'primary' or 'secondary'
 * writer is used to determine the leader

Author: mnd999

common/src/main/java/apoc/util/Util.java

@@ -687,9 +687,9 @@ public static boolean isWriteableInstance( GraphDatabaseAPI db )
     {
         var socketAddress = db.getDependencyResolver().resolveDependency( Config.class ).get( BoltConnector.advertised_address ).toString();
         GraphDatabaseService systemDb = db.getDependencyResolver().resolveDependency( DatabaseManagementService.class ).database( SYSTEM_DATABASE_NAME );
-        String role = systemDb.executeTransactionally( "SHOW DATABASE $databaseName WHERE address = $socketAddress",
-                Map.of( "databaseName", db.databaseName(), "socketAddress", socketAddress ), result -> Iterators.single( result.columnAs( "role" ) ) );
-        return role.equalsIgnoreCase( "LEADER" )  || role.equalsIgnoreCase( "standalone" );
+        Boolean writer = systemDb.executeTransactionally( "SHOW DATABASE $databaseName WHERE address = $socketAddress",
+                Map.of( "databaseName", db.databaseName(), "socketAddress", socketAddress ), result -> Iterators.single( result.columnAs( "writer" ) ) );
+        return writer;
     }
 
     /**

core/src/test/java/apoc/util/UtilTest.java

@@ -114,4 +114,8 @@ public void testMerge() {
             db.executeTransactionally("MATCH (n:Test) DETACH DELETE n");
         }
     }
+    @Test
+    public void testIsWritableInstance() {
+        assertTrue(Util.isWriteableInstance(db));
+    }
 }