Move some network tests from Neutron to Tempest

Tests for core network resources should move from Neutron to Tempest.
For the cases with identical names (already exist in Tempest), apply
the implementation from Neutron, which is slightly better implemented.

Change-Id: I63102ba02a20f0ba27cd322262dbcff4e5a48178
Depends-On: Ic4a6292390a88e732f7460cf558c479baa8771b1
Related-Bug: #1552960
2 files changed