config: add support for pagination in api-request list queries

[Hampapur Ajay]

Currently a collection of resource-type can be queried by GET using an anchor of
a. None - entire list of resources of resource-type are picked up
b. list of backref ids
c. list of parent ids

There is no support for pagination at all. To support this 2 query parameters will be added in GET of collection
a. paginate_start - a string indicating the uuid from which to grab the next <paginate_count> worth of items. To get the first set paginate_start can be set to empty string or paginate_count can be set to a str(number)
b. paginate_count - a string representing count of items to be retrieved in this GET. If paginate_start is set but paginate_count is not then return a default number of items

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/8412
Submitter: Hampapur Ajay (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Reviewed: https://review.opencontrail.org/8412
Committed: http://github.org/Juniper/contrail-controller/commit/9c38e2794fe086f477db21bc7bbf4c4b1c7b7cae
Submitter: Zuul
Branch: master

commit 9c38e2794fe086f477db21bc7bbf4c4b1c7b7cae
Author: Hampapur Ajay <email address hidden>
Date: Tue Mar 17 13:46:30 2015 -0700

config: staging for pagination support for GET of collection.

This commit sets up dbe_list to receive additional parameters
from <type>s_http_get from vnc_api_server_gen.py autogen code.

Change-Id: If0cd35e56990f0b0b2b22b96b5e9cd1c6080fee2
Partial-Bug: #1433304

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/32285
Submitter: Hampapur Ajay (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/32285
Submitter: Sachin Bansal (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Reviewed: https://review.opencontrail.org/32285
Committed: http://github.com/Juniper/contrail-controller/commit/2d8a2bf77beea4d2c560470af1c5b17aaa8a0251
Submitter: Zuul (<email address hidden>)
Branch: master

commit 2d8a2bf77beea4d2c560470af1c5b17aaa8a0251
Author: Hampapur Ajay <email address hidden>
Date: Tue May 30 10:24:28 2017 -0700

Implement pagination for collection in VNC API.

Add support for marker and count pagination parameters
in list API upon which collection is returned in batches.
A marker is returned back in every batch which is expected
to be sent back to get the next one. Marker is generated
by db layer (for efficient location of next batch) and
annotated by higher layers if needed (e.g. for sending
'shared' elements of collection).

Closes-Bug: #1433304
Change-Id: I4f728696c898cccdc339a1ec066ced14f7668558