Emit process_nanos from LookupOperator

[idegtiarenko]

While profiling esql execution I noticed that most of the operators emit process_nanos except LookupOperator that emits total_time_in_millis & total_time:

...
          {
            "operator": "LuceneSourceOperator[maxPageSize = 1236, remainingDocs = 997]",
            "status": {
              "processed_slices": 1,
              "processed_queries": [
                "*:*"
              ],
              "processed_shards": [
                "base:0"
              ],
              "processing_nanos": 143595, <------
              "slice_index": 0,
              "total_slices": 1,
              "pages_emitted": 3,
              "slice_min": 0,
              "slice_max": 0,
              "current": 2147483647,
              "rows_emitted": 3
            }
          },
          {
            "operator": "ValuesSourceReaderOperator[fields = [key, value, value.keyword]]",
            "status": {
              "readers_built": {
                "key:column_at_a_time:BlockDocValuesReader.SingletonLongs": 3,
                "stored_fields[requires_source:true, fields:0, sequential: false]": 3,
                "value.keyword:column_at_a_time:BlockDocValuesReader.SingletonOrdinals": 3,
                "value:column_at_a_time:null": 3,
                "value:row_stride:BlockSourceReader.Bytes": 3
              },
              "process_nanos": 1135976, <------
              "pages_processed": 3,
              "rows_received": 3,
              "rows_emitted": 3
            }
          },
          {
            "operator": "ProjectOperator[projection = [1, 2, 3]]",
            "status": {
              "process_nanos": 40508, <------
              "pages_processed": 3,
              "rows_received": 3,
              "rows_emitted": 3
            }
          },
...
          {
            "operator": "LookupOperator[index=languages input_type=LONG match_field=key load_fields=[language{f}#38, language.keyword{f}#39] inputChannel=0]",
            "status": {
              "received_pages": 2,
              "completed_pages": 2,
              "total_time_in_millis": 6, <------
              "total_time": "6ms",        <------
              "emitted_pages": 3,
              "total_terms": 3
            }
          },
...

This change updates LookupOperator to emit process_nanos as well.

[elasticsearchmachine]

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