add custom labels support for pod-based network policies

[fvanderwielen]

Describe the feature request
I would like to set custom labels on the pods of the helm chart, so they match with active network policies on the cluster I need to work on.

What you are trying to do
I want to deploy mockserver via helm, to a cluster I cannot do the administation of myself. The cluster has active network policies, using matchLabels to allow the pods to be exposed. To be clear, these network policies are set by administration, and it is not within my possibilities to modify them to run on namespace (like the mockserver helm docs suggest)

The solution you'd like
I want to be able to give the pods in the mockserver helm chart custom labels.

Describe alternatives you've considered

• I reached out to cluster administration, but the respond that namespace based network policies is not possible for them.
• administration also suggested the use of kustomize to patch the helm chart with the needed labels. But this does not combine with the current deployment tools we already use for other applications within this project.
• For now I am going to attempt to copy and modify the mockserver helm chart to allow custom labels myself.

ps. I definitely want to give compliments on mockserver. I have been a software developer professionally for well over 10 years, and this project is well above the norm. It was really easy to get up and running locally with docker, and configuring it with curl is also really great, along with the other features allowing for incredible flexibility.

[fvanderwielen]

I downloaded the chart (V 5.15.0 from the tagged release, not 5.14.0 linked on the website), and modded in a podLabels Value similarly to podAnnotations, to get this to work as described. Let me know if a PR would be appreciated.