Add helm chart

[vdice]

Describe your changes

Adds a Helm chart, building off of https://github.com/spinkube/runtime-class-manager/pull/132 where the bulk of the work was done.

With @voigt's blessing I have created a new PR with a handful of fixes and changes (see commit history). Testing has shown the runtime-class-manager to work properly on kind and AKS clusters.

Issue ticket number and link

https://github.com/spinkube/runtime-class-manager/issues/47

Checklist before requesting a review

• [x] I have performed a self-review of my code
• [ ] If it is a core feature, I have added thorough tests.
• I tested the changes with the following distributions:
  • [x] Kind
  • [ ] MiniKube
  • [ ] MicroK8s
  • [ ] Rancher RKE2
  • [x] Azure AKS
  • [ ] GCP GKE (Ubuntu nodes)
  • [ ] AWS EKS (AmazonLinux2 nodes)
  • [ ] AWS EKS (Ubuntu nodes)
  • [ ] Digital Ocean Kubernetes