We want to add the Service Mesh Control Plane Namespaces counter metric defined by:

• A label "smcp_version", which indicates the version of the version of the service mesh control plane (e.g. 2.1, 2.2, 2.3, 2.4, etc).
• A label "smcp_mode", with two possible values: "multi-tenant" or "cluster-wide"
• Value: The number of namespaces in the mesh.

This metric should be exposed by the istio-operator and be collected by Telemetry

Acceptance criteria:

• Create the servicemesh_members metric
• Ensure this metric can be collected by Telemetry
• Unit tests