Thin client: connecting to thick client node is broken

• Thick clients have thin client connector enabled by default
• ClientClusterGroupGetNodesEndpointsResponse excludes client nodes

As a result:

• Thin client connects to a thick client node
• Gets node endpoints - current connection is not there
• Thin client closes current connection immediately

The following test demonstrates the problem. While setForceServerMode is deprecated, there could be other reasons for other nodes to be unreachable.

    @Test
    public void testConnectToThickClient() {
        TcpDiscoverySpi discoSpi = new TcpDiscoverySpi()
                .setIpFinder(new TcpDiscoveryVmIpFinder(true))
                .setForceServerMode(true);

        IgniteConfiguration igniteCfg = new IgniteConfiguration()
                .setDiscoverySpi(discoSpi);

        try (Ignite ignored = Ignition.start(igniteCfg);
             IgniteClient client = Ignition.startClient(new ClientConfiguration())
        ) {
            assertNotNull(client);
        }
    }

Potential solutions:

• Disable client connector on thick client nodes by default (breaking change?)
• Fix ClientClusterGroupGetNodesEndpointsResponse to include thick client nodes if connector is enabled, and let the client decide whether to connect to them or not