Feat/update kpt v1 simplified

This MR updates agentk configuration to render with kpt v1. Configuration is set in kpt-setter-configmap.yaml and then rendered before applying to the cluster.

This branch is a simplified alternative to the bases/overlays layout in !610 (closed); it reduces resource configurations into one folder.

This enables a workflow where a package can be retrieved, kustomized, and then deployed per GitLab group (perhaps the same project as the agent config file??):

1. kpt pkg get {pkg}{version}
2. (optional) sed '/^ name-prefix: /s/:.*$/: "GitLabGroupName"/' kpt-setter-configmap.yaml
3. kpt fn render
4. echo -n "<agent token" > secrets/agent.token
5. kpt live init
6. kustomize build | kpt live apply

Thoughts @nagyv-gitlab?

Closes #205 (closed)