Implement rate-limiting

[nimishamehta5]

Some things to think about:

• On what basis / key to apply the rate-limit? (tool name, resource name, IP address, etc.)
• Should we have different limits for different tools?
• Can we utilize the k8s client's in-built rate limiting mechanisms? (config.QPS & config.Burst)

[JAORMX]

This is a really good thing to consider. Probably it should be by client IP?