Support remote datasets from s3 compliant data sources

[frcroth]

URL of deployed dev instance (used for testing):

• https://___.webknossos.xyz

Steps to test:

• Set up a minio server
• Create a bucket in that server and upload a dataset to it (do this via the web console)
• Create an access key on the server
• Explore this dataset with URL: "s3://<minio-server-ip>:<minio-server-port>/<bucket-name>/<root-key-of-the-dataset>"
• View dataset
• Also explore S3 datasets to ensure they still work

Alternative repl testing

import java.net.URI;
import com.scalableminds.webknossos.datastore.datavault.S3DataVault;
implicit val ec: scala.concurrent.ExecutionContext = scala.concurrent.ExecutionContext.global;
import com.scalableminds.webknossos.datastore.datavault.VaultPath;
val key = com.scalableminds.webknossos.datastore.storage.S3AccessKeyCredential(name="someKey", accessKeyId="FhXRPMiC9KWMBh9WXF54", secretAccessKey="9eVWQYZckmshjIMsebOBkztMqfHpC5t88bFWOMhc", user="", organization="");
val uri =  new URI("s3://10.191.1.63:8000/somezarr/e75_zarr_local");
val minioVault = new S3DataVault(Some(key), new URI("s3://10.191.1.63:8000/somezarr/e75_zarr_local"));
val vp = new VaultPath(uri, minioVault);
(vp / "color" / "1" / "credentials.json").readBytes().get("")

TODOs:

• ...

Issues:

• fixes Support S3-compliant storages #7432

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(Please delete unneeded items, merge only when none are left open)

• Updated changelog
• Considered common edge cases
• Needs datastore update after deployment

[fm3]

Looking good :) Added a comment on code style. Feel free to merge after tackling that