Add support for HUAWEI Object Storage Service (OBS)

[imhy]

Add support for Huawei Object Storage Service (OBS)

OBS - is a scalable service that provides secure, reliable cloud storage for massive amounts of data.

Motivation

Adding support for OBS in smart open extends of list supported transports and add ability third party libraries to work with this service more native way. For Ray project I created PR based on this functionality.

Tests

Done

@mpenkov @piskvorky