Project Dependency: Add tracked ref filter option

What does this MR do and why?

Add filter tracked ref to project dependency page.

Note:

1. The BE schema accepts the arguments, but the actual filtering logic is still in development.
2. The default branch is not pre-selected, it will be tackled in a later MR

References

Screenshots or screen recordings

Before	After

How to set up and validate locally

1. Enable FF:
   • project_dependency_tracked_ref
   • vulnerabilities_across_contexts
2. Clone any project that will generate dependency findings
   • ex. https://gitlab.com/gitlab-org/govern/threat-insights-demos/security-reports-with-dependency-paths
3. Run a successful pipeline
4. Navigate to the Project > Dependency List
5. Click on the tracked ref dropdown, it will make the GraphQL request

MR acceptance checklist

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Related to #601839