[FEATURE] Add test for 3 nodes cluster

[BewareMyPower]

Is your feature request related to a problem? Please describe. There is an unload bug that cannot be reproduced on a 2 nodes cluster. See #1180

When there are 3 brokers or more in cluster, one broker may not receive the bundle load and unload event if the bundle is not owned by the broker, in this case the broker will not able to invalidate the look up cache for the topics in this bundle.

The existing DistributedClusterTest only tests a 2 nodes cluster.

Describe the solution you'd like Create 3 PulsarService instances in DistributedClusterTest and verify KoP works well after the bundle ownership changes.