[common] Cannot create headless service

[HonoluluHenk]

Describe the bug
With the current common chart, it is not possible to create a headless service because setting the ClusterIP is tied to the service type "LoadBalancer"

Version of Helm and Kubernetes:
Helm Version: **Kubernetes Version**:
not relevant

Which chart:

common -> _service.yaml

How to reproduce it (as minimally and precisely as possible):
Create a service with type: ClusterIP
Set the service property clusterIP: None

Anything else we need to know:
Implemented in PR #131