Add basic telemetry for start-proxy Action

[mbg]

This PR adds support for basic telemetry to the start-proxy Action. Due to the nature of start-proxy, we are careful here to:

• Not report error messages and stack traces, if the Action fails. We only report that it fails.
• If the Action succeeds, we only report the types of the registries that are configured and used by CodeQL.

Risk assessment

For internal use only. Please select the risk level of this change:

• Low risk: Changes are fully under feature flags, or have been fully tested and validated in pre-production environments and are highly observable, or are documentation or test only.

Merge / deployment checklist

• Confirm this change is backwards compatible with existing workflows.
• Consider adding a changelog entry for this change.
• Confirm the readme and docs have been updated if necessary.

[Copilot]

Pull Request Overview

This PR adds basic telemetry support to the start-proxy Action, enabling collection of success/failure status and registry type information while avoiding sensitive data exposure. The implementation carefully excludes error messages and stack traces for security reasons.

• Added StartProxy action name to the telemetry enum
• Implemented success/failure status reporting with registry type tracking
• Wrapped main proxy logic in try-catch for proper error handling and telemetry

Reviewed Changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated 2 comments.

File	Description
src/status-report.ts	Added StartProxy to ActionName enum and reordered entries alphabetically
src/start-proxy-action.ts	Added telemetry reporting infrastructure, success status function, and error handling wrapper

[esbena]

LGTM with one internal question to be answered elsewhere