adding changes from kube-mixin

jsonnet: fix label selector for coredns ServiceMonitor

Signed-off-by: ArthurSens <arthursens2005@gmail.com>

.github: write temporary file to /tmp

jsonnet: improve all-namespaces addon

Signed-off-by: paulfantom <pawel@krupa.net.pl>

Fix scheduler and controller selectors for Kubespray

feat(grafana): add env parameter for grafana component

scripts: include kube-rbac-proxy and config-reloader in version upgrades

Fix adding private repository

`imageRepos` field was removed and the project no longer tries to compose image strings. Now the libraries use `$.values.common.images` to override default images.

Signed-off-by: paulfantom <pawel@krupa.net.pl>

Enable tests for kubernetes 1.21

jsonnet: drop storage_operation_errors_total and storage_operation_status_count as those are deprecated in k8s 1.21

Signed-off-by: paulfantom <pawel@krupa.net.pl>

Unpin jsonnet dependencies

Improvements in addMixin function.

Signed-off-by: paulfantom <pawel@krupa.net.pl>