users/customers do not have a reasonable number of buckets anymore,
this is why we must avoid overpopulating cluster endpoints, instead
move the bucket monitoring to a separate endpoint.
some of it's a breaking change here for a couple of metrics, but
it is imperative that we do it to improve the responsiveness of
our Prometheus cluster endpoint.
Bonus: Added new cluster metrics for usage, objects and histograms
enable linter using golangci-lint across
codebase to run a bunch of linters together,
we shall enable new linters as we fix more
things the codebase.
This PR fixes the first stage of this
cleanup.
