Improve the `helm` deployer

[kpouget]

Name of Feature or Improvement

Get the helm deployer in a decent state to ease the deployment of the main branch

Description of Problem the Feature Should Solve

• namespace cannot be configured, it's hardcoded to kube-system
• mcad deployment labels are inconsistent (app: custom-metrics-apiserver)
• mcad deployment name is different from ODH (minor, but better for consistency)
• mcad default image mcad-controller:latest does not work [in OpenShift at least], ErrImagePull
• the AppWrapper CRD is not deployed