Add a way to collect results from all pages of a PaginatedResponse

[iamkubi]

PaginatedResponse needs a method to gather all of the results from all pages into a list. Something like:

response = api.nodes.list_nodes()
nodes = response.collect()

This is useful when you want all of the results for all pages up front and don't need to iterate over multiple pages.

[iamkubi]

Fixed by c094443