[REQUEST]: Document AWS S3 Input support for GZ/ZIP files

### Description

The AWS S3 Input docs doesn't mention the ability to harvest `.gz/.zip` files in S3 buckets in general.

Seems starting 8.0 + 7.9+ we started supporting decompression of files from AWS even if their extension is not `.gz/.zip` via https://github.com/elastic/beats/pull/18764 via content type detection.

The pages to update are:
- https://www.elastic.co/guide/en/beats/filebeat/current/filebeat-input-aws-s3.html
- Any integration page referencing AWS S3 Input directly (Custom S3 Integration, AWS S3 Integration, ...)

### Resources

I think we should cover the details of this capability.

In particular, we also need to explain/clarify if the use of compressed files might impact the `expand_event_list_from_field` feature (from the code, it seems not running if the content-type is not "application/json").

### Collaboration

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### Point of contact.

**Main contact:** @elastic/obs-cloud-monitoring

**Stakeholders:**