[Bug] Object key order matters when exporting to CSV - ideally shouldn't be?

[nktnet1]

Which package is this bug report for? If unsure which one to select, leave blank

@crawlee/core

Issue description

1. Create a dataset
2. Push an object, e.g.

   { name: 'John', age: 30 }
   

3. Push another object with the same keys, but different order, e.g.

   { age: 42, name: 'Adam' }
   

4. Export the dataset to a CSV file
5. Observe that the output is

   name,age
   John,30
   42,Adam
   

I would've expected the order of keys->columns to be determined by the first object in the dataset, e.g.

name,age
John,30
Adam,42

Or otherwise, the importance of key order should be noted somewhere in the docs.

Code sample

import { Dataset } from 'crawlee';

const main = async () => {
  const datasetName = 'example-dataset';

  let dataset = await Dataset.open(datasetName);
  await dataset.drop();

  dataset = await Dataset.open(datasetName);

  await dataset.pushData({ name: 'John', age: 30 });
  await dataset.pushData({ age: 42, name: 'Adam' });

  await dataset.exportToCSV(`${datasetName}.csv`);
  console.log((await dataset.getData()).items);
};

void main();

Package version

3.11.5

Node.js version

v20.17.0

Operating system

MacOS, Linux (Arch)

Apify platform

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I have tested this on the next release

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