Use gitlabSubscriptionsPreviewBillableUserChange in overage modal
Problem:
Don't show overage when adding guests to Ultimate group.
Proposal:
We have introduced preview to check overages at the moment of addition in !90195 (merged). FE should call this as API and use hasOverage
, seatsInSubscription
and newBillableUserCount
to show/hide overage modal. We should be able to remove most of the FE calulations and use the BE service purely.
Tests consideration:
We have plenty of tests cases to cover, TBD add a separate issue with their description and related integration tests