Unit testing of NATS helm charts

[kejne]

In our team where we have quite a lot of Helm charts, it has been very helpful to create unit tests for the charts using https://github.com/helm-unittest/helm-unittest.

I think it would be helpful for contributors to have unit tests in place for charts and I wouldn't mind to start to create some unit tests for some basic parts as well as a simple github actions to run tests on PR:s.

Is this something you guys would like to consider?