feat (molgenis-vault): Add backup cronjob

Needs to run under service account created by the etcd-operator subchart so there's some template magic needed to figure out what it's called.

molgenis-vault/templates/_helpers.tpl

@@ -1,3 +1,11 @@
+{{/* See https://github.com/helm/helm/issues/4535 */}}
+{{- define "call-nested" }}
+{{- $dot := index . 0 }}
+{{- $subchart := index . 1 }}
+{{- $template := index . 2 }}
+{{- include $template (dict "Chart" (dict "Name" $subchart) "Values" (index $dot.Values $subchart) "Release" $dot.Release "Capabilities" $dot.Capabilities) }}
+{{- end }}
+
 {{/* vim: set filetype=mustache: */}}
 {{/*
 Expand the name of the chart.