Enhanced Compatibility for various Prometheus Installations

[snorwin]

Is your feature request related to a problem? Please describe.

When Prometheus is installed in a Kubernetes cluster independently, outside the OperatorHub.io ecosystem, the default service account may not be set to prometheus-k8s. As a consequence, when ArgoCD creates Prometheus instances, it assumes the service account is named prometheus-k8s, leading to operational issues.

Describe the solution you'd like

Introduce a new optional field, e.g., .spec.prometheus.serviceAccountName, in the ArgoCD CR.

Describe alternatives you've considered

Manually crafting the service account and its associated role bindings to align with the desired service account configuration.

Additional context
None