[UDF] empty result from execute prepared statement in JS udf

To repro:

• load travel-sample
• create udf: curl -s -k -X POST http://172.23.104.91:8093/evaluator/v1/libraries/n1ql -u Administrator:password -H 'content-type: application/json' -d 'function execute_prepare() { var query = execute lyon_airport; var acc = []; for (const row of query) { acc.push(row); }

  return acc;}'

• CREATE OR REPLACE FUNCTION execute_prepare() LANGUAGE JAVASCRIPT AS "execute_prepare" AT "n1ql" ;
• prepare statement ( \set -query_context "default:"): prepare lyon_airport as SELECT airportname FROM `travel-sample`.inventory.airport WHERE city = "Lyon";
• check prepare statement:
  cbq> select name, statement from system:prepareds where name like "lyon%";

• {

  "requestID": "83afcfd4-bd4c-4346-9c7a-63776405d921",

  "signature": {

  "name": "json",

  "statement": "json"

  },

  "results": [

  {

  "name": "lyon_airport(default:)",

  "statement": "prepare lyon_airport as SELECT airportname FROM `travel-sample`.inventory.airport WHERE city = \"Lyon\";"

  }

  ],

  "status": "success",

• execute function

returns empty result set:

cbq> execute function execute_prepare();

{

    "requestID": "aaa3a63a-00b3-4a0c-a033-8c6cfdf31721",

    "signature": null,

    "results": [

    []

    ],

    "status": "success",

    "metrics": {

        "elapsedTime": "18.843017ms",

        "executionTime": "18.670471ms",

        "resultCount": 1,

        "resultSize": 2,

        "serviceLoad": 6

    }

}