Add health check endpoint

[jsanant]

Is your feature request related to a problem? Please describe.
We deployed kWatch in our k8s environment and recently due to load the pod crashed due to OOMKilled

Describe the solution you'd like
Add a health check endpoint to make sure the pod is reachable.

❯ curl localhost:8060/healthcheck   
OK

[CyberneTech]

@abahmed Can I take this up?

[abahmed]

@CyberneTech yes sure