As the name suggests, an `Address` represents a particular IP Address.
This can be a `Service` or a `Workload`.

The address type has the following goals:
* It should support (but not require) on-demand lookups.
  * Specifically, ztunnel should be able to send a request to the control plane to answer "I got a request to send traffic to 1.1.1.1, what is 1.1.1.1?"

Envoy has stopped requested them; if there are no subscriptions they update will be ignored. If Envoy later watches these certificates again,
a new one will be generated on demand.

## Configuration

| Variable | Description |
| - | - |
|CA_ADDR|Address of CA, defaults to discoveryAddress|