[Part 1] Foundation for user billing pricing information experiment

What does this MR do and why?

We plan to add pricing information to the user-level billing page to capture conversion opportunities from users who currently reach a dead end when searching for pricing details. To validate whether this is a good idea, we’re running an experiment. This MR includes all the foundational work required, such as introducing a new scope to list all groups that are either free or in a trial period. Using this scope, we target only users who own or administer at least one free or trial group. Users who are already paid members and not on trial will be excluded.

References

https://gitlab.com/gitlab-org/gitlab/-/issues/555682

Screenshots or screen recordings

Control	Candidate

How to set up and validate locally

1. Testing the scope
   1. Make sure Simulate SAAS is enable, if not please enable it form here
   2. Open rails console using the command rails c
   3. Run this code Group.free_or_trial.count
   4. Make sure the query is executed without any issue.
2. Testing the candidate variant
   1. Make sure simulate SAAS is enabled.
   2. open rails console with rails c
   3. Assign a user user = User.first
   4. Enable the flag for this user Feature.enable(:user_billing_pricing_information, user)
   5. Login with the user you enabled the feature flag for
   6. Open profile > billings page
   7. You should see a blank page, it means the candidate version is rendered.

MR acceptance checklist

Evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Related to #555682