Add Packages and Registries menu

What does this MR do?

This MR moves the Packages & Registries menus from the HAML file to the new project sidebar refactor.

Screenshots (strongly suggested)

Before the MR	After the MR

Does this MR meet the acceptance criteria?

Conformity

• 📋 Does this MR need a changelog?
  • I have not included a changelog entry because it's a tooling change.
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Separation of EE specific content

Related to #326434 (closed)