Add stream query interface for promise based pool

I'd like to propose adding a stream based query interface when using the promise based interface, that would act similarly as the stream method that exists on the Query interface.

For example, given the following code:

import mysql, { PoolConnection } from 'mysql2';

const pool = mysql.createPool({
  database: 'db',
  host: '127.0.0.1',
  multipleStatements: true,
  password: 'password',
  user: 'root',
});

(async () => {
  const connection = await new Promise<PoolConnection>((resolve, reject) => {
    pool.getConnection((err, conn) => {
      if (err) {
        reject(err);
      } else {
        resolve(conn);
      }
    });
  });
  const stream = connection
    .query({
      sql: 'SELECT 1',
    })
    .stream();

  stream.on('data', (data) => {
    console.log({ data });
  });

  await new Promise<void>((resolve, reject) => {
    stream.on('end', () => {
      resolve();
    });
    stream.on('error', (err) => {
      reject(err);
    });
  });
  connection.release();
})()
  .then(() => {
    console.log('done');
  })
  .catch((err) => {
    console.error(err);
  })
  .finally(() => {
    pool.end();
    process.exit(0);
  });

As far as I'm aware, there's no way then to rewrite this to use mysql2/promise instead as .query always returns a Promise. Given that I don't think that interface can change, I think it'd be good to see an additional queryStream method that works the same as query, but instead returns a Readable object, similar to query().stream().

Start with the promise-based pool query interface and its TypeScript definitions, then compare them with the Query interface and its existing stream method linked in the issue. Trace how promise queries are implemented and identify the tests covering pool queries. Done means the promise pool exposes a queryStream method returning a Readable with equivalent streaming behavior and appropriate type coverage.