The [**List all members of a group or project including inherited and invited members**](https://docs.gitlab.com/api/members/#list-all-members-of-a-group-or-project-including-inherited-and-invited-members) endpoint of the **Group and project members API** allows the usage of the `show_seat_info` boolean to include the `is_using_seat` boolean for each project member in the returned slice. However, in the [`client_go`](https://pkg.go.dev/gitlab.com/gitlab-org/api/client-go#ProjectMembersService.ListAllProjectMembers) package, this `show_seat_info` flag is not supported. I propose to add support for this flag. ## Implementation Guide - Follow the `CONTRIBUTING.md` guide to get your local development environment set up. - Add `ShowSeatInfo` to the `ListGroupMembersOptions` struct in `group_members.go`. - Add `IsUsingSeat` to the `GroupMember` struct in `group_members.go`. - Add `ShowSeatInfo` to the `ListProjectMembersOptions` struct in `project_members.go`. - Add `IsUsingSeat` to the `ProjectMember` struct in `project_members.go`. - Update unit tests in `group_members_test.go` and `project_members_test.go`. - Run `make reviewable` to ensure the code is ready for review.