[s3] Allow usage of S3-Compatible endpoints

[nanderson94]

Problem Description

Many cloud providers and self-hosted object storage software utilize S3-compatible APIs which are compatible with boto3 with some extra configuration. Currently, those configuration options are not exposed to the users.

Proposed Solution

Pass-through options commonly utilized by S3-compatible endpoints:

• An endpoint-url override, users may set this to https://ceph-rgw.example.com/ for example.
• An option to select path-style bucket addressing as opposed to virtual-host

Alternatives

N/A

Additional Context

Rclone's documentation provides a good list of S3-compatible providers: https://rclone.org/s3/

[nanderson94]

Changes have been drafted in my fork: https://github.com/elastic/connectors/commit/379fe6c099f0c01fa8aa3614bd38a00b0e3a18af