Custom Metadata Support for Workers in Temporal UI and CLI

[deepika-awasthi]

Is your feature request related to a problem? Please describe.
Workers currently only support identity information, which appears in the UI and CLI via temporal describe task queue. There's no way to attach custom metadata to workers (like environment, version, team ownership, etc.) unless using worker deployments or worker versioning. For users not using these features, there's no operational visibility into worker-specific metadata.

Describe the solution you'd like
Add support for custom metadata on workers that can be set during worker registration and viewed in both the Temporal UI and CLI. Example for Java SDK:

javaWorkerOptions options = WorkerOptions.newBuilder()
    .setIdentity("worker-1")
    .setMetadata(Map.of(
        "environment", "production",
        "version", "1.0.0",
        "team", "platform"
    ))
    .build();

The metadata should be displayed in the UI and in CLI commands like temporal describe task queue.
Describe alternatives you've considered