[radar-mockserver] Add mockserver charts

[pvannierop]

This PR will add mockserver with a mockserver-config that facilitates the creating of expectations.

[github-actions]

Great PR! Please pay attention to the following items before merging:

Files matching charts/*/values.yaml:

• Is the PR adding a new container? Please reviewer, add it to the models (internal process)
• Is the PR adding a new parameter? Please, ensure it’s documented in the README.md

This is an automatically generated QA checklist based on modified files.

[keyvaann]

The lint is failing.

[keyvaann]

Ideally we want to mirror this chart in our own repository but I don't know how much it's necessary

[pvannierop]

Can we make a dependency on a chart in the external dir?

[pvannierop]

Ah apparently we can:

# Chart.yaml
dependencies:
- name: nginx
  version: "1.2.3"
  repository: "file://../dependency_chart/nginx"

[keyvaann]

We have done it like this in the past
https://github.com/RADAR-base/radar-helm-charts/blob/main/charts/velero-s3-deployment/Chart.yaml#L11

I'm not sure if the file:// approach will work but if it does, it's fine then.

[pvannierop]

Yes, it works

[pvannierop]

@keyvaann I have added the external chart! Can you please re-review?

[keyvaann]

LGTM