Story (Required)

As a User, I would like to have a command line option for providing a label selector to the GitOps Controller manager,
So that, I can select a subset ArgoCD instance(s) that the particular GitOps Controller manager need to manage.

Background (Required)

As the number of ArgoCD instances increase, there is a need to scale up the number of Openshift GitOps controller manager instances, in a way that each controller manager instance, manages a subset of ArgoCD instance(s).
This can be achieved by applying specific labels to the ArgoCD instances and each controller instance, can then be configured to manage only those ArgoCD instances that match the label selector.

Out of scope

• Only single label selector need to be supported.
• Do we need an option to configure using environment variable (similar to DISABLE_DEX) ?
  * Use of the newly added parameters

  Approach (Required)

• In main.go file add an optional flag similar to this to store the label selector as a string value
• Validate that a the label selector is valid as per the kubernetes specificattion for labels and is of the format key=value

Acceptance Criteria (Mandatory)

• The newly added value is optional and does not throw any error when no value is provided.
• When a label selector value is provided, then the values is stored correctly in the newly created variable.
• The options show up in the documentation of ControllerOptions
• CI checks are green