Support for S3 access points for remote storage.

[ktchu]

Depending on IT policies, it may not be possible to use an S3 bucket for DVC remote storage because it may not be possible to obtain bucket-level access permissions. In these situations, S3 access points for DVC remote provide a possible alternative because access policies can be attached to access points that grant access permissions at the "subdirectory" level.

One way to add support for S3 access points would be allow the DVC remote storage URLs to be AWS ARN identifiers. Unfortunately, the current URL processing implementation is unable to handle ARN identifiers because it attempts to interpret the portion of the ARN after the first colon as a port:

Port could not be cast to integer value as 'aws:s3:us-west-2:123456789012:accesspoint'

[isidentical]

AWS Reference: https://docs.aws.amazon.com/AmazonS3/latest/userguide/s3-arn-format.html

[gokulchittaranjan]

The source of this problem is:
return infer_storage_options(path)["path"] (init.py in dvc_s3 folder)

This issue could be fixed upstream in [filesystem_spec] (fsspec/filesystem_spec@a1cf9ba)