Save resource verification level on create

What does this MR do and why?

This MR updates Catalog::Resources::CreateService to fetch the verification level from a resource's root namespace and save it with the resource. It also updates the verification_level field on the Resource model so it has the same values as the verification_field on VerifiedNamespace.

Changelog: changed

Issue: #455530 (closed)

Screenshots

You can see the badges showing up as expected below 👍

Note: we don't yet have a badge for verified creators, but the backend will support it once we add it

How to set up and validate locally

1. Pick a project that is not already a catalog resource

2. Create a verified namespace record for the project's root namespace:

   project = Project.find_by_full_path('FULL_PATH')
   
   Ci::Catalog::VerifiedNamespace.create(namespace: project.root_namespace, verification_level: :gitlab_maintained)

3. Set up the project to be a valid catalog resource: https://docs.gitlab.com/ee/ci/components/#create-a-component-project

4. Create a release for the resource

5. Check in the Rails console that a resource record was created with the correct verification level

   project = Project.find_by_full_path('FULL_PATH')
   
   project.catalog_resource.gitlab_maintained? # => true