Accept custom registered endpoints

The review drops usage of skip_path() filter in the related tests
and uses raw_request() instead.

Normally a swift url is organised as host:port/info and
host:port/v1/AUTH_<tenant-id>, see
https://docs.openstack.org/api-ref/object-store/
But RadosGW API is organised as host:port/swift/info and
host:port/swift/v1/AUTH_<tenant-id>, see
https://docs.ceph.com/docs/master/radosgw/config-ref/#swift-settings

Close-bug: 1799981
Change-Id: I6a932639a05defe0f04c600afcc35a19662937af
4 files changed