Add Keystone V3 TRUST support

* Added two configuration parameters.
  "fs.swift.service.<name>.domain.name" and
  "fs.swift.service.<name>.trust.id"

Change-Id: Ia456a702477c6dc0a25401fd6caddff239412cce
Partial-implements: blueprint edp-swift-trust-authentication
Merge "Add Keystone V3 TRUST support"