scout/advise: first iteration of the `src scout advise` subcommand

Created by: jasonhawkharris

Refactor

• create a universal config object for the scout tool
• before, each subcommand had its own config type
• add kube package for repetitive kubernetes actions across sub commands

First iteration of scout advise

• scout advise gives recommendations for resources allocations based on current usage

Test plan

Ships with unit tests. Manually tested on healthy and unhealthy instances of sourcegraph (k8s and Docker).