Rename GCS resource to Bucket resource / cloud storage resource / other catchy name

[ghost]

Expected Behavior

The GCS resource now supports S3 through the use of a boto configuration file. See #1361 for where this support was added for artifact uploading and comment from Andrea #1258 (comment) describing its use to get the GCS resource speaking to S3.

So the "GCS" resource now supports S3 but is still named "GCS". We should fix this to indicate it supports other bucket types.

[ghost]

Hm, we should also probably document its usage as well. Will create a separate issue for that.

[ghost]

We've decided to punt on this for the time being. Lots of churn in PipelineResources and there are cases that the boto config can't handle due to, it seems, problems in the way the s3 implementation is done in gsutil. For example, trying to use Minio in a sidecar and accessing it through localhost doesn't seem to work.

[ghost]

I'm going to close this issue. Given the work going on with the pipeline resources revamp / prototyping it seems more likely that we'll end up in a place where a dedicated S3 resource type could be introduced and maintained as part of the catalog or something similar instead of messing with the existing GCS resource.