Co-authored-by: Michael Marshall <mmarshall@apache.org>
### Motivation
There was a suggestion [in a dev mailing list discussion](https://lists.apache.org/thread/bgkvcyt1qq6h67p2k8xwp89xlncbqn3d) that the Helm chart's appVersion should be used as the default image tag.
### Additional context
There are some limitations in Helm. It is not possible to set "appVersion" from the command line. There's in an open feature request https://github.com/helm/helm/issues/8194 to add such a feature to Helm.
### Modifications
- change default values.yaml and set the tags for the images that use the Pulsar image to an empty value
- add "defaultPulsarImageTag" to values.yaml
- add a helper template "pulsar.imageFullName" that contains the logic to fall back to .Values.defaultPulsarImageTag and if it's not set, falling back to .Chart.AppVersion
- use the helper template in all other templates that require the logic
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.
