Changes to Create an inventory model

request property data/type was restricted to a list of enum values

added the new optional request property data/attributes/manual_stock_decrement

added the new optional request property data/attributes/put_stock_transfers_on_hold

added the new optional request property data/attributes/stock_reservation_cutoff

the request property data/attributes/strategy became optional

the type request property default value inventory_models was removed

added the new inventory_models enum value to the request property data/type

added the media type application/vnd.api+json for the response with the status 201