The kafka/kineses sampler route should have the ability to list topics/streams

### Description

Right now in the console when selecting Kafka ingestion you then need to enter the bootstrap servers and type in the topic.


It would be really cool if the user could enter the bootstrap servers and get a listing of topic on those servers saving them from having to type it in.

### Motivation

This would remove a keyboard step from the console which is potentially a source of mistakes (typo in topic name) or slowdown (forgetting the topic name and having to look it up).

Start with the console's Kafka ingestion flow and the kafka/kinesis sampler route mentioned in the issue. Trace how bootstrap servers and the topic are currently entered and submitted; done means presenting available topics or streams after the server details are entered and allowing one to be selected.

Written by the indexing model from the issue text.