[Feature Request] Support `worker_version` selectors in `WorkerResourceTemplate`

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

We run a self-hosted Temporal Server and use WorkerResourceTemplate to create one HPA per worker version, using the Temporal Server's approximate_backlog_count metric through Datadog.

The Temporal Server already exports worker_version on the backlog metric. However, the controller injects only temporal_worker_deployment_name, temporal_worker_build_id, and temporal_namespace. We currently rename the server's separate deployment/build labels in the collector to match those selectors.

Describe the solution you'd like

Ideally, metric selector injection should be configurable, so Temporal Worker Controller's users can choose the label names and how their values are derived from the worker deployment, build ID, and Temporal namespace. Supporting worker_version is our immediate use case, but a general configuration mechanism would also accommodate other collector and metrics-adapter conventions.

For our setup, this should provide an opt-in way to generate a worker_version selector from the worker version associated with each rendered resource.

Additional context

• Controller Helm chart: 0.29.1; self-hosted Temporal Server: 1.31.0.
• Temporal Server constructs the deployment-version metric tag from the deployment name and build ID.