Convert pre-install batch job from shell to Go code

This GitHub issue is to convert the pre-install Kubernetes job from shell script to Go code.

### Why:
Bash in YAML makes it
a) hard to understand what this does
b) extremely difficult to test

### Where:
https://github.com/Azure/osm-azure/blob/a317fec83d7d9cb61066daf5ad8627124acfab17/charts/osm-arc/templates/osm-label.yml#L122-L187

### How:
I propose we
1. create a Go package in this repo - use Go K8s client instead of `cURL`
2. write tests for it
3. create a new Dockerfile
4. create release pipeline
5. push the image in the appropriate container registries
6. use the new container image instead of Alpine: https://github.com/Azure/osm-azure/blob/a317fec83d7d9cb61066daf5ad8627124acfab17/charts/osm-arc/templates/osm-label.yml#L123