add flexibility to define a custom/alternate namespace for the operator vs scylla-operator with the helm operator

[tluck]

What should the feature do?

allow one to easily use an alternate namespace for the operator deployment.
e.g.:

helm install scylla-operator scylla-operator --create-namespace --namespace myspecificname -f scylla-operator.yaml

What is the use case behind this feature?

some organizations have specific naming requirements for their k8s environments and will not allow the default name ("hard-coded")

Anything else we need to know?

No response