Remove instance:node_filesystem_usage:sum

jsonnet: update component versions

Regenerate dashboards and prometheus alerts

Merged https://github.com/kubernetes-monitoring/kubernetes-mixin/pull/463 to remove duplicate entries for memory usage, however I'd like to move these changes to the Prometheus-Operator helm chart(https://github.com/helm/charts/pull/23024#issuecomment-661967101). I've regenerated the dashboards/alerts.

Add PrometheusOperatorListErrors and fix PrometheusOperatorWatchErrors threshold 

Watch error alert

chore(jsonnet):   update jsonnet to master

prometheus-operator.libsonnet: Add PrometheusOperatorWatchErrors alert

pulls in recent performance improvement changes to speed up rendering

resolves #537

jsonnet/kube-prometheus: Bump default versions of prometheus and alertmanager

enable etcd latency metrics in kube-apiserver

kube-apiserver has a histogram etcd_request_duration_seconds that
measures latency between the kube-apiserver and etcd instance.
This metrics is currently dropped by cluster-prometheus. Enable
this metrics so we have visibility into etcd latency.

We ensured that this does not enable other unwanted metrcis

count by(name) ({name=~"etcd_request.+"})

etcd_request_duration_seconds_bucket
etcd_request_duration_seconds_count
etcd_request_duration_seconds_sum

Update the Issue templates to redirect to GitHub Discussions.

Update kubernetes-mixin to remove KubeAPILatencyHigh & KubeAPIErrorsHigh

Fix typo

Bump Grafana to v6.7.4

Updated prometheus adapter deployment to use a multi arch image repo

Make node-exporter listening address configurable

Fix AlertmanagerConfigInconsistent alert

Update prometheus-adapter endpoint

Previously the alert would fire when the number of Alertmanager pods
didn't match the number of replicas defined in the Alertmanager spec
even though all the running pods had the same configuration hash. This
type of issue is already covered by KubeStatefulSetUpdateNotRolledOut
(and possibly KubePodNotReady), having AlertmanagerConfigInconsistent
also active in this situation creates unnecessary noise.

With this change, the alert expression only returns when Alertmanager
pods have different configuration hash values irrespective of the number
of pod replicas. The message annotation has also been enhanced to report
the configuration hash for each pod.

Signed-off-by: Simon Pasquier <spasquie@redhat.com>