Add History tab to CloudActivations
Problem
Now that Admin users can forward CloudActivations (implemented in #6138 (closed)), they should be able to see the object's history and the email addresses each CloudActivation has been forwarded to.
This is a follow up from https://gitlab.com/gitlab-org/customers-gitlab-com/-/merge_requests/6961#note_1336052349.
Proposal
Add the CloudActivation model to the PAPER_TRAIL_AUDIT_MODEL so the History Tab is available for it the same way it is for Licenses.
Result
The History Tab is available for CloudActivation the same way it is for Licenses.