This changes the format of the truncation report in the server logs to show how many elements were omitted at each level of the truncated JSON object.

Description of Linked Ticket

When running a simple find command with over 5000 elements in $in clause, the output in the log line is: 

 ... _id:{$in:[ <truncated list of 377 out of 5000 values> ] ...
{
    "truncated" : {
        "command" : {
            "filter" : {
                "_id" : {
                    "$in" : {
                        "377" : {
                            "type" : "string",
                            "size" : 29
                        }
                    }
                }
            }
        }
    },

I'd love to know how many actual values were truncated which is what I thought it would show but it seems instead to show how many are written.