Add new app for dependency proxy

What does this MR do and why?

This MR creates a new vue app to refactor the dependency proxy haml view to vue. The app is not yet 'hooked up' anywhere and this is step one of a two or three MRs needed to implement the change.

Screenshots or screen recordings

⚠ this screenshot is not yet functional, is just an example ⚠

How to set up and validate locally

Apply this patch: enable-new-dep-proxy.patch

Navigate to group => packages_and_registries => dependency proxy

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #322842 (closed)