Families for enterprise/stripe integrations (#1699)

* Add PlanSponsorshipType to static store

* Add sponsorship type to token and creates sponsorship

* PascalCase properties

* Require sponsorship for remove

* Create subscription sponsorship helper class

* Handle Sponsored subscription changes

* Add sponsorship id to subscription metadata

* Make sponsoring references nullable

This state indicates that a sponsorship has lapsed, but was not able to
be reverted for billing reasons

* WIP: Validate and remove subscriptions

* Update sponsorships on organization and org user delete

* Add friendly name to organization sponsorship

src/Core/Models/Data/OrganizationUserOrganizationDetails.cs

@@ -33,5 +33,6 @@ namespace Bit.Core.Models.Data
         public string PrivateKey { get; set; }
         public Guid? ProviderId { get; set; }
         public string ProviderName { get; set; }
+        public string FamilySponsorshipFriendlyName { get; set; }
     }
 }