_id may support sorting

[haveTryTwo]

In some scenarios, when using the search after mechanism, as "Doc values are disabled on this field so sorting on it requires to load a lot of data in memory. Instead it is advised to duplicate (client side or with a set ingest processor) the content of the _id field in another field that has doc value enabled and to use this new field as the tiebreaker for the sort", by copying _id to other fields, _id can be sorted, thus avoiding further copying