* Added nullable OrganizationId to EventModel
* Added EventType Organization_ClientExportedVault
* Updated CollectController to save the event Organization_ClientExportedVault
* Added OrganizationExportResponseModel to encapsulate Organization Export data
* Added OrganizationExportController to have a single endpoint for Organization vault export
* Added method GetOrganizationCollections to ICollectionService to get collections for an organization
* Added GetOrganizationCiphers to ICipherService to get ciphers for an organization
* Updated controllers to use new methods in ICollectionService and ICipherService
* added enum values for new events
* hooked up directory sync event
* upgraded the OrganizationUpgrade ReferenceEvent
* Added metadata to the OrganizationUserInvited event noting if this is the first event sent from an organization
* Added metadata to the AdjustedSeats event
* Implemented vaultImported event
* Implemented FirstGroupAdded event
* Implemented FirstCollectionAdded event
* Implemented FirstSecretAdded event type
* Implemented SalesAssisted reference event
* changed events to match updated requirements
* renamed an event enum