Add id to payload of get_item_by_id_query

[wbazant]

Add id to payload of get_item_by_id_query.

It's nice to have consistent return objects. I had some code for retrieving items from a board, wanted to reuse it with the other query for a list of ids, and couldn't before this change.

Also it seems potentially incorrect to not ask for the ID: when asking for more than one id, we might want the IDs of returned objects, and without asking for them we have to assume come in the same order - I don't know whether they do or don't, but adding the ids back to the payload seemed like a worse solution than asking for them back.