add support for Baidu Cloud BOS(object store) as a new underfs source

Description

to support Baidu Cloud BOS system which is an object store(https://cloud.baidu.com/doc/BOS/ProductDescription.html#BOS.E6.98.AF.E4.BB.80.E4.B9.88.EF.BC.9F), we add a new underfs named "bos"

Environment

None

Status

Assignee

byteman

Reporter

byteman

Labels

None

Time tracking

40h

Components

Fix versions

Affects versions

master

Priority

Minor
Configure