metrics: convert from CommonJS to ES Modules

[trivikr]

Converts the scripts in metrics from CommonJS to ES Modules
Part of modernizing metrics scripts as a follow-up to #3697

Testing

The ESM setup was deployed on processlogs, and verified that logs are being processed

Before

2024-07-14 09:26:39.929 PDT EVENT TYPE:  OBJECT_FINALIZE
2024-07-14 09:26:39.929 PDT Node version is: v20.15.0
2024-07-14 09:26:39.929 PDT BUCKET cloudflare-logs-nodejs
2024-07-14 09:26:39.929 PDT FILENAME 20240714/20240714T162556Z_20240714T162556Z_7d9dc7c0.log.gz
2024-07-14 09:26:39.929 PDT PROCESSEDFILENAME 20240714/20240714T162556Z_20240714T162556Z
2024-07-14 09:26:39.930 PDT INSIDE CREATE PIPELINE
2024-07-14 09:26:40.275 PDT String length: 33351
2024-07-14 09:26:40.275 PDT Array Length: 73
2024-07-14 09:26:40.580 PDT Upload complete: 20240714/20240714T162556Z_20240714T162556Z

After

2024-07-14 09:27:28.041 PDT EVENT TYPE:  OBJECT_FINALIZE
2024-07-14 09:27:28.041 PDT Node version is: v20.15.1
2024-07-14 09:27:28.041 PDT BUCKET cloudflare-logs-nodejs
2024-07-14 09:27:28.041 PDT FILENAME 20240714/20240714T162608Z_20240714T162715Z_91d12f82.log.gz
2024-07-14 09:27:28.041 PDT PROCESSEDFILENAME 20240714/20240714T162608Z_20240714T162715Z
2024-07-14 09:27:28.042 PDT INSIDE CREATE PIPELINE
2024-07-14 09:27:28.706 PDT String length: 6535414
2024-07-14 09:27:28.709 PDT Array Length: 13500
2024-07-14 09:27:29.149 PDT Upload complete: 20240714/20240714T162608Z_20240714T162715Z

[trivikr]

This PR has been open for 72+ weekend hours, and is ready to merge.

[trivikr]

cc @nodejs/build