Make event controllers highly available

[daurer]

The default helm chart for the argo event controller is only using a single replica: https://github.com/argoproj/argo-helm/blob/fb807031a28b136be3901601f7aca69e6cfa23fe/charts/argo-events/values.yaml#L161

Simply increasing the replica count did not work: "Failed to load global configuration file"

Need to figure out how to add HA to all critical event controllers.