[PM-17777] sponsorships consume seats (#5694)

* Admin initiated sponsorships now use seats similarly to inviting an organization user

* Updated f4e endpoint to not expect a user ID, and instead just send a boolean

* Fixed failing tests

* Updated OrganizationUserReadOccupiedSeatCountByOrganizationIdQuery to ensure both left and right sides are selecting the same columns

src/Core/AdminConsole/Repositories/IOrganizationUserRepository.cs

@@ -18,6 +18,15 @@ public interface IOrganizationUserRepository : IRepository<OrganizationUser, Gui
     Task<ICollection<OrganizationUser>> GetManyByUserAsync(Guid userId);
     Task<ICollection<OrganizationUser>> GetManyByOrganizationAsync(Guid organizationId, OrganizationUserType? type);
     Task<int> GetCountByOrganizationAsync(Guid organizationId, string email, bool onlyRegisteredUsers);
+
+    /// <summary>
+    /// Returns the number of occupied seats for an organization.
+    /// Occupied seats are OrganizationUsers that have at least been invited.
+    /// As of https://bitwarden.atlassian.net/browse/PM-17772, a seat is also occupied by a Families for Enterprise sponsorship sent by an
+    /// organization admin, even if the user sent the invitation doesn't have a corresponding OrganizationUser in the Enterprise organization.
+    /// </summary>
+    /// <param name="organizationId">The ID of the organization to get the occupied seat count for.</param>
+    /// <returns>The number of occupied seats for the organization.</returns>
     Task<int> GetOccupiedSeatCountByOrganizationIdAsync(Guid organizationId);
     Task<ICollection<string>> SelectKnownEmailsAsync(Guid organizationId, IEnumerable<string> emails, bool onlyRegisteredUsers);
     Task<OrganizationUser?> GetByOrganizationAsync(Guid organizationId, Guid userId);