Fix: Change Base Labels to CamelCase for ArgoCD ApplicationSets Compatibility

[Courtlane]

Description:

This pull request addresses an issue with ArgoCD ApplicationSets where labels containing '-' cannot be reused due to invalid characters. To resolve this, I have updated the base labels to use camelCase instead.

Example:

apiVersion: argoproj.io/v1alpha1
kind: ApplicationSet
metadata:
  name: my-applicationset
  namespace: argocd
spec:
  goTemplate: true
  goTemplateOptions: ["missingkey=zero"]
  generators:
    - clusters:
        selector:
          matchLabels:
            "clusterType": "usercluster"
        values:
          clusterId: '{{.metadata.labels.kubermatic-argocd-bridge/cluster-id}}'

Here are the log errors from ArgoCD that prompted these changes:

Message: error appending templated values for cluster: failed to replace templated string: failed to replace templated string with rendered values: failed to parse template {{.metadata.labels.kubermatic-argocd-bridge/cluster-id}}: template: :1: bad character U+002D '-'
Reason: ApplicationGenerationFromParamsError

Changes:

• Updated all base labels to camelCase.
• Ensured compatibility with ArgoCD ApplicationSets by removing invalid characters.

Testing:

• Confirmed that ArgoCD ApplicationSets can now reuse the labels without issues.