deploy-sourcegraph-dhall: cadvisor: implement generate reading from config

Created by: uwedeportivo

right now the generate function in cadvisor https://github.com/sourcegraph/deploy-sourcegraph-dhall/blob/master/src/base/cadvisor/generate.dhall doesn't read the configuration that is passed into it.

we want to read enough configuration to support configuring these params:

https://github.com/sourcegraph/deploy-sourcegraph-dogfood-k8s/blob/ca1a4d1a7e678f6fa65abd2fdab5047fff31000e/generated/params.sh

• implement templating logic
• maybe add more fields in the global config
• if needed: implement transformations

provide an example pipeline config that declares the changes from dogfood for prometheus.