Enable dependency proxy manifest lists

What does this MR do and why?

In this MR we are:

• enabling the previously created manifest_list
• connecting the pagination to the query
• hiding the pagination when is not necessary
• adding an empty state illustration

⚠ the API paginated sorting is bugged, another MR has been open to fix it: !73844 (merged)

Screenshots or screen recordings

Before

After

With manifests	Without Manifests	No pagination and tooltip

Screencapture

ManifestList

This screencapture is old.

How to set up and validate locally

1. Login into rails console: rails c
2. FactoryBot.create(:dependency_proxy_manifest, group: Group.first)
3. Repeat the above a few times
4. Go to the first group in your GDK (usually gitlab-org) dependency proxy

Note that the console may complain on missing fixture_file_upload in that case add this to the console and try again

def fixture_file_upload(*args, **kwargs)
  Rack::Test::UploadedFile.new(*args, **kwargs)
end

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 #250865 (closed)