* azureblob - Add support for Azure Storage Emulator to test things locally.
Testing - Verified changes by testing manually.
* docs: update azureblob docs to reflect support of storage emulator
This change includes removing older azureblob storage SDK, and getting
parity to existing code with latest blob storage SDK.
This change is also pre-req for addressing #2091
* Fixup bitrot (rclone and Azure library)
* Implement Copy
* Add modtime to metadata under mtime key as RFC3339Nano
* Make multipart upload work
* Make it pass the integration tests
* Fix uploading of zero length blobs
* Rename to azureblob as it seems likely we will do azurefile
* Add docs