Fixes #38055 - Fix future-dated subscriptions

[jeremylenz]

What are the changes introduced in this pull request?

Problem 1:
Candlepin's GET owners/{owner_key}/products endpoint, called by Katello::Resources::Candlepin::Product.all, recently added a new param, active. When the param is not included, it apparently causes Candlepin to omit (some?) products with future-dated subscriptions. Sending the param active=include should restore the previous behavior. This affects Candlepin version 4.4.15 and above.

Problem 2:
The "Add Subscriptions" page does not display future-dated subscriptions, e.g. subscriptions whose start date is in the future. Sending the add_future param should fix that.

Considerations taken when implementing this change?

I don't think this should break anything, since the param would just be ignored on previous CP versions.

What are the testing steps for this pull request?

1. Obtain a manifest with a future-dated subscription and no other subscriptions

2. Import into a new organization

Without this PR: Manifest import fails with

Validation failed: Subscription can't be blank

From another org with a valid manifest imported, the "Add Subscriptions" page does not show any future-dated subscriptions available to add.

After:
Manifest import succeeds
You can see any future-dated subscriptions on the Add Subscriptions page. Compare with access.redhat.com > Subscription allocations > your manifest > Add subscriptions. The available subscriptions in Satellite should include future-dated ones just like this page does.

[jeremylenz]

This is what made tests pass locally for me. But I am not sure if this test is correct or not. It does make sense that the number of imported products would vary now that I'm sending include=active, but I wouldn't expect numbers this big. I looked inside the fixture manifest files and didn't see 342 of anything..