Handle pagination keys in lister response

Right now, NetworkClientJSON.deserialize_list() returns the
first key-value pair from the lister response.

But the lister response might differ when pagination is enabled
with pagination_max_limit set to some value. There will be one
additional key-value pair like {resource}s-links: {href:, rel: ..},
which deserialize_list() does not handle

This patch attempts to fix this bug

Change-Id: Ic554abb0342288f9226cc358dc930cc150d098a2
Closes-bug: #1398811
Merge "Handle pagination keys in lister response"