Add trial and subscription blocks to Subscription Activation Form

What does this MR do?

It adds "Free trial" and "Subscription" blocks to the cloud licensing activation form.

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• 📋 Does this MR need a changelog?
  • I have included a changelog entry.
  • I have not included a changelog entry because the change is under a feature flag.
• Code review guidelines
• Separation of EE specific content

Related to #325739