Remove remaining stub tests and dependency on legacy stub server (neo4j#1088)

* Remove remaining stub tests and dependency on legacy stub server

Reactive Testkit backend enabled a lot of Testkit tests to run on reactive driver. This update removes dependency on legacy stub server that is no longer maintained.

The remaining stub tests have been removed since there are similar tests in Testkit already, the tests and their respective Testkit alternatives are provided below:
- `DirectDriverBoltKitIT.shouldStreamingRecordsInBatchesRx` -> `TestIterationSessionRun.test_half_batch` - Both test result consumption in batches.
- `DirectDriverBoltKitIT.shouldDiscardIfPullNotFinished` -> `TestIterationSessionRun.test_discards_on_session_close` - Unlike the original, Testkit test consumes one record and discards the rest using session `run` intead of tx function. Based on its name, the original test purpose was to check if discard happens when result stream is not consumed in full and the suggested test covers this.
- `RoutingDriverBoltKitIT.shouldHandleLeaderSwitchAndRetryWhenWritingInTxFunctionRX` -> `RoutingV4x4.test_should_write_successfully_on_leader_switch_using_tx_function` - Both check leader failure handling.

One of examples that dependended on stub server has been brought in line with the rest of examples and uses `DatabaseExtension` to manage server.

* Renamed RoutingDriverBoltKitIT to ResolverIT

Author: injectives

driver/src/test/java/org/neo4j/driver/GraphDatabaseTest.java

@@ -50,11 +50,16 @@
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
+import static org.neo4j.driver.Logging.none;
 import static org.neo4j.driver.internal.logging.DevNullLogging.DEV_NULL_LOGGING;
-import static org.neo4j.driver.util.StubServer.INSECURE_CONFIG;
 
 class GraphDatabaseTest
 {
+    private static final Config INSECURE_CONFIG = Config.builder()
+                                                        .withoutEncryption()
+                                                        .withLogging( none() )
+                                                        .build();
+
     @Test
     void throwsWhenBoltSchemeUsedWithRoutingParams()
     {

driver/src/test/java/org/neo4j/driver/integration/ResolverIT.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) "Neo4j"
+ * Neo4j Sweden AB [http://neo4j.com]
+ *
+ * This file is part of Neo4j.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.neo4j.driver.integration;
+
+import org.junit.jupiter.api.Test;
+
+import org.neo4j.driver.Config;
+import org.neo4j.driver.Driver;
+import org.neo4j.driver.GraphDatabase;
+import org.neo4j.driver.net.ServerAddress;
+import org.neo4j.driver.net.ServerAddressResolver;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+import static org.neo4j.driver.Logging.none;
+
+class ResolverIT
+{
+    @Test
+    void shouldFailInitialDiscoveryWhenConfiguredResolverThrows()
+    {
+        ServerAddressResolver resolver = mock( ServerAddressResolver.class );
+        when( resolver.resolve( any( ServerAddress.class ) ) ).thenThrow( new RuntimeException( "Resolution failure!" ) );
+
+        Config config = Config.builder()
+                              .withoutEncryption()
+                              .withLogging( none() )
+                              .withResolver( resolver )
+                              .build();
+        final Driver driver = GraphDatabase.driver( "neo4j://my.server.com:9001", config );
+
+        RuntimeException error = assertThrows( RuntimeException.class, driver::verifyConnectivity );
+        assertEquals( "Resolution failure!", error.getMessage() );
+        verify( resolver ).resolve( ServerAddress.of( "my.server.com", 9001 ) );
+    }
+}