Azure
don't default the delimiter for list blob hierarchy to slash
Regarding the list-blobs endpoint. Azure handles an empty delimiter query parameter as such (as if it was not given). But Azurite defaults it to a / (slash). This behaviour was added by @XiaoningLiu, but I cannot determine the exact reason.
It causes incompatibility issues. E.g. in the Azure Storage Explorer; the returned flat list of blobs is empty when there are in fact blobs in the container. And also in minio, which uses the azure storage go library which always sets the delimiter query parameter.
This PR removes the defaulting behaviour.
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I could. But Azure SDK for JS, used as client in the existing tests, does not send an empty delimiter. I'd have to write a test at lower level (http). Don't know if you want that.
