feat(argocd-understack): add common labels to the Applications

[cardoe]

Add the ability to apply common labels to all of the Applications to
give the ability to search and sort ArgoCD on the labels.

[skrobul]

This is very repeatable and may be difficult to maintain. What do you think of DRYing it out and having a helper like:

{{- define "understack.appLabelsBlock" -}}
{{- with .Values.appLabels }}
labels:
{{- toYaml . | nindent 2 }}
{{- end -}}
{{- end }}

and then in each of the apps just call:

{{- include "understack.appLabelsBlock" $ | nindent 2 }}

[cardoe]

This is very repeatable and may be difficult to maintain. What do you think of DRYing it out and having a helper like:

{{- define "understack.appLabelsBlock" -}}
{{- with .Values.appLabels }}
labels:
{{- toYaml . | nindent 2 }}
{{- end -}}
{{- end }}

and then in each of the apps just call:

{{- include "understack.appLabelsBlock" $ | nindent 2 }}

Good point. I've done this.