Add multi-version support with version selector to refresh Dependency-Track metrics

[boukadam-relyens]

Hi team,

First, thank you for the great work on this plugin — it's been extremely useful in our Backstage setup.

I’d like to propose an enhancement to add multi-version support for components/projects.
Currently, the plugin displays metrics for a single version (usually the latest), but many projects in Dependency-Track maintain multiple active versions. Being able to inspect metrics per version would greatly improve visibility and governance.

Proposed feature

• Detect and list all available versions of the selected project/component from Dependency-Track.
• Add a version selector (dropdown) in the UI.
• When a version is selected, refresh and display the metrics for that specific version.
• Optionally cache or memoize version lists to reduce API calls.

Why this would be valuable

• Many teams maintain several release lines in parallel (e.g., LTS, stable, and next).
• Security posture can vary significantly per version.
• This would align the plugin with how Dependency-Track structures data.
• It improves auditability and aligns with organizational security workflows.

Happy to discuss implementation details or open a PR if the feature is accepted.

Thanks!