Investigate alternative approach to CRD upgrades

[burmanm]

Is your feature request related to a problem? Please describe.
The current CRD upgrader was designed for k8ssandra 1.x installations, it does not work correctly for cass-operator chart.

We need a way to update CRDs preferably without external pod that does it.

Describe the solution you'd like
Could we try to use templates + a set to update the CRD if it isn't installed?

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Add any other context or screenshots about the feature request here.

[burmanm]

Using templates has its issue when updating the CRD..

helm upgrade -n k8ssandra k8ssandra charts/cass-operator --set updateCRDs=true --reuse-values
Error: UPGRADE FAILED: rendered manifests contain a resource that already exists. Unable to continue with update: CustomResourceDefinition "cassandradatacenters.cassandra.datastax.com" in namespace "" exists and cannot be imported into the current release: invalid ownership metadata; label validation error: missing key "app.kubernetes.io/managed-by": must be set to "Helm"; annotation validation error: missing key "meta.helm.sh/release-name": must be set to "k8ssandra"; annotation validation error: missing key "meta.helm.sh/release-namespace": must be set to "k8ssandra"

Since Helm wants to own an item per release it installs.