Inferred Chanset can be viewed in campaigned admin

[maxime-rainville]

Description

When you publish a page, it creates an "Infered" changeset object. This ChangeSet can be access by ID in campaign admin and you get an error when you try to interact with it.

Steps to reproduce

• Publish a page
• Look up the latest ID of your changeset in the DB
• Access the campaign with this ID in Campaign-admin

Expected outcome: You get a 400/404 error page Actual: You see a campaign

Acceptance criteria

• [ ] Campaign admin does not let you directly access inferred change set as campaigns.
• [ ] A reasonable error is shown if you try to directly access an inferred change set and a proper HTTP error code is returned.
• [ ] Inferred change set are not shown in the campaign list.
• [ ] If this feature uses a GraphQL query, both GraphQL v3 and v4 refuse to returned inferred change set.

Pull request

• [ ] https://github.com/silverstripe/silverstripe-campaign-admin/pull/228

[sabina-talipova]

Sequencing:

1. Filter the changeSet in the CampaignAdmin class by IsInferred === false (? Find out the purpose of IsInferred value)
2. If the passed ID does not exist in ChangeSet table or the ID did not pass the filter, return 404.
3. In the CampaignAdminList React Component, catch the 404 and return the appropriate content.

[maxime-rainville]

Just summarizing some discussion @sabina-talipova had today.

For our use case, it's probably not worthwhile differentiating between the scenario where the user asks for a non-existent changeset and for an existing inferred change set.

I'll see if I can get some design review for the 404 error page. Maybe post a screen shot of what it currently looks like in your PR for now.

Adding some Behat test to cover this possibility is probably more of a nice-to-have, but it's a good way to get your behat set up working.