Update metrics-server chart and images

[manuelbuil]

This PR updates the metrics-server images to v0.7.1 and makes a big version bump on the chart, which was pretty old.

Chart-update relevant changes:

• Starts consuming the tarball from the https://github.com/kubernetes-sigs/metrics-server/releases
• We don't need to carry patches on clusterrole.yaml and api-service.yaml anymore because the changes are already in the upstream code.
• We reduced the patches in deployment.yaml because some are already in the upstream code.
• tests is removed.
• Some manifests changed names, e.g. metrics-server-deployment.yaml.patch is now deployment.yaml

Three changes to remember (in case of issues):
1 - We were using --kubelet-preferred-address-types=InternalIP since upstream did not define anything there. Now upstream uses --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname as default. I left what upstream uses as InternalIP is still prioritized.
2 - We were using priorityClassName: system-node-critical since upstream had that, even though it was commented. Now upstream uses priorityClassName: system-cluster-critical as default. I left what upstream uses even though system-node-critical is the highest priority.
3 - Note that upstream clusterrole now includes "confimaps" and does not include "nodes/stats". I decided to keep what's upstream