Support endpoint type in CLI tests

This patch reads the endpoint_type parameter of the various option
groups of Tempest and passes it as the --(os-)endpoint-type parameter
of the Openstack CLI clients. This allows Tempest to be run in several
network configuration where, for instance, the publicURL is not directly
reachable.

Change-Id: I87f874b9c3fd4fd15907dc933c1ebb62ad4e6e4b
Merge "Support endpoint type in CLI tests"