Future-dated amendments in Subscription Admin Page

Proposal

This is a continuation of https://gitlab.com/gitlab-org/gitlab/-/issues/334426. We want to actually implement the UI to display information about future dated subscription amendments/versions.

Once the UX design is finalized in #337531 (closed), we can start implementing both the backend and frontend.

Send Future subscription info thru seat link is created to handle the CustomersDot's side of implementation.

Requirements

On the subscription history table:-

• In the Name Column add a (i) info account with a tooltip that displays billing persons email address and underneath the company.
• Remove the Email column
• Remove the Company column
• Valid From date should use starts_at (no change)
• Activated on date should use created date of License file (this means blank for future subscriptions)
• We should not show non-cloud future-dated license subscriptions in the table. All non-cloud future-dated licenses should only be added by license file upload.
• Remove "Added on" column (if it has already been added)