ESQL: Profile should include row_count by default

[nik9000]

Description

Our profiles look like:

            {
              "operator": "EvalOperator[evaluator=ConcatEvaluator[values=[ToStringFromLongEvaluator[field=Attribute[channel=4]], LiteralsEvaluator[lit=[3a]], ToStringFromLongEvaluator[field=CaseEagerEvaluator[conditions=[ConditionEvaluator[condition=EqualsKeywordsEvaluator[lhs=Attribute[channel=3], rhs=LiteralsEvaluator[lit=[73 70 61 6e]]], value=Attribute[channel=11]]], elseVal=Attribute[channel=12]]]]]]",
              "status": {
                "process_nanos": 84322048,
                "pages_processed": 480
              }
            },

It'd be really useful and cheap to include the number of positions processed. We could just positions += page.getPositionCount() and that's pretty close to free. A single extra + per page should be fine.

[elasticsearchmachine]

Pinging @elastic/es-analytical-engine (Team:Analytics)