Fixes#125
### Motivation
The default images in the values.yaml are in docker hub. This PR allows us to provide image pull secrets for the containers which will allow us to get around Docker Hub's rate limiting if the nodes are not logged into Docker Hub.
### Modifications
Added a new template to generate `imagePullSecrets`, and included them in the deployments and statefulsets. This will only add them if they are specified under `images.imagePullSecrets`
### Verifying this change
- [] Make sure that the change passes the CI checks.
It remains possible to override the current release namespace by setting
the `namespace` value though this may lead to having the helm metadata
and the pulsar components in different namespaces
Fixes#66
### Motivation
Trying to deploy the chart in a namespace using the usual helm pattern fails for example
```
kubectl create ns pulsartest
helm upgrade --install pulsar -n pulsartest apache/pulsar
Error: namespaces "pulsar" not found
```
fixing that while keeping the helm metadata and the deployed objects in the same namespace requires declaring the namespace twice
```
kubectl create ns pulsartest
helm upgrade --install pulsar -n pulsartest apache/pulsar --set namespace=pulsartest
Error: namespaces "pulsar" not found
```
This is needlessly confusing for newcomers who follow the helm documentation and is contrary to helm best practices.
### Modifications
I changed the chart to use the context namespace `.Release.Namespace` by default while preserving the ability to override that by explicitly providing a namespace on the commande line, with the this modification both examples behave as expected
### Verifying this change
- [x] Make sure that the change passes the CI checks.
Co-authored-by: Elad Dolev <elad@firebolt.io>
### Motivation
Give the ability to deploy multi-cluster instance on K8s clusters with non-default `clusterDomain`, and connect to external configuration-store
### Modifications
- give the ability to change cluster's name
- give the ability to change `clusterDomain`
- fix external configuration store functionality
- use broker ports variables
- use label templates, and add `component` label in several places
### Verifying this change
- [x] Make sure that the change passes the CI checks.
