port attach_interfaces and server_address tests into v3 part2

This port interface client into v3 and the attach_interface tests
into v3, also port server_address tests into v3

Partially implements blueprint nova-v3-api-tests

Change-Id: I0701ace05c6ae7feb72a6a00949ae830f63ff853
port test_simple_tenant_usage into nova v3 part1

This changeset only copies the v2 files into the appropriate v3
directories unchanged. This is being tried in order to make
reviewing of the porting easier as gerrit will display only what
is actually changed for v3 rather than entirely new files.

Partially implements blueprint nova-v3-api-tests

Change-Id: I0ef1d85fe7ce7e9ca836c6e3a5a447df9941eccd
Merge "port attach_interfaces and server_address tests into v3 part2"
Merge "port test_simple_tenant_usage into nova v3 part1"