Some functions in api/neutron use @memoized decorator,
but @memoized decorator cannot handle request.GET (an instance of
QueryDict) because a weakref to WSGIRequest is not hashable.
(Note that @memoized decorator can handle a dict itself)
What we actually need is the content of request.GET.
By using .dict() method we can ensure arguments which
@memoized can handle are passed to api.neutron functions.
This pattern is used only in api.rest.neutron and
not used in other codes.
Closes-Bug: #1706348
Change-Id: Ibb38ad1d95af1cd90a1fedd834602f444010c151
0c1e179b3c