View change helper functions

added helper functions for sharding. this is kind of how it looks like.

please feel free to modify anything or ask me to change something.

also oops i just realized my formatter changed way too much in containers.py...

    with KVSTestFixture(conductor, dir, log, node_count=4) as fx:
        c = KVSMultiClient(fx.clients, "client", log)
        conductor.add_shard("shard1", conductor.get_nodes(0, 2))
        fx.broadcast_view(conductor.get_shard_view())

        # examples of modifying shards
        conductor.add_shard("shard2", conductor.get_nodes(2, 3))
        conductor.add_node_to_shard("shard2", conductor.get_node(3))
        conductor.remove_node_from_shard("shard1", conductor.get_node(0))
        conductor.remove_shard("shard1")