Use go-cloud to support multiple object stores

[kakkoyun]

Is your feature request related to a problem? Please describe.
Since we have multiple backends to support, for ease of integration we can use go-cloud for integration.

Describe the solution you'd like
This integration would give us multiple blob store integration. Check out the details https://github.com/google/go-cloud/blob/master/internal/website/content/howto/blob/_index.md

This could help to solve issues #61 #63 #62.

[spier]

If go-cloud really works as well as we hope, we would also go back and port some existing cloud storage backends to use go-cloud.

However as this would not give the users any new features, we will do this in a future release. maybe v1.2.0, maybe even later.