NSX: add nsx switch lookup to dhcp and metadata operations

The operations in questions were still using the neutron network
uuid as the nsx switch uuid, but this is no longer valid.

Close-bug: #1312439

Change-Id: I0f4bf02bb176c5c3914c7dd7e8249121af1b5a79
NSX: change api mapping for Service Cluster to Edge Cluster

NSX 4.2 GA has tweaked the naming for certain resources. Edge
Cluster vs Service CLuster is one of them.

Closes-bug: #1312822

Change-Id: Id4ddd99128c5e82e7a40c2d9e7385b272549cc3e
Merge "NSX: change api mapping for Service Cluster to Edge Cluster"
Merge "NSX: add nsx switch lookup to dhcp and metadata operations"