Resolve "Admin Panel page - information about failed jobs"

What does this MR do and why?

We add a table with a list of failed jobs to the batched background migrations - show view.

Related to: #351102 (closed)

Screenshots or screen recordings

How to set up and validate locally

1. Visit /admin/background_migrations/
2. Click on the batched background migration
3. See the failed jobs

If you need to populate data:

Open rails console and execute:

failed_migration = FactoryBot.create(:batched_background_migration, :failed)
FactoryBot.create(:batched_background_migration_job, :failed, batched_migration: failed_migration)

Numbered steps to set up and validate the change are strongly suggested.

MR acceptance checklist

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