Decide on an authentication mechanism for UI analytics

# Spike

Investigate the different options for authentication into Kafka.
Originates from #3684
The [prototype](https://github.com/guardicode/monkey-analytics/activity?ref=prototype), for reference

## Objective
Determine how the UI will authenticate to the Kafka broker. Keep in mind that the UI will need credentials, so this should include how the credentials are stored in the Island build.

## Output
Create an issue to implement Kafka authentication into the UI.