Add support for metrics on the Lookout HTTP server

[Sovietaced]

It would be nice to have metrics for lookout to keep track of response codes, duration, etc.

[dejanzele]

Hey,

Thank you for raising this issue!

It appears we already have similar functionality available as lookout_request_duration. However, the specific implementation for this metric is currently missing.

This should be relatively straightforward to add, and we'd welcome a PR from you if you're interested. Alternatively, our team can pick this up at a later stage, though we can't commit to a specific timeline at the moment. Please let us know how you'd prefer to proceed!