Make helm charts compatible with Helm v3 (i.e. by dropping CRD templating)

Problem to solve

Currently the Helm charts cannot be applied using Helm3 (current stable) because of the missing/templated CRDs. With Helm 3 being stable and moving along very quickly, requiring Helm 2 will absolutely keep people from considering this operator or even taking it for a quick spin on their minikube or KIND cluster.

Further details

Helm 3 has a special treatment of CRDs: https://v3.helm.sh/docs/topics/charts/#custom-resource-definitions-crds Most importantly is the fact that they cannot be templated and will not be upgraded by Helm.

Proposal

Statically provide the CRDs in their own folder, just like i.e. https://github.com/zalando/postgres-operator/pull/738 did for the Zalando Postgres Operator project.

Testing

Links / references