Improve share-network list API filtering

Add filtering share-network list by creation date, associated security
service ID, project ID (for admin context only).

Limit share network list using 'offset' and 'limit' options.

Add policy rule for 'get_all_share_networks' action.

Remove 'status' field from returned share nerwork's view,
as share_network model doesn't have such attribute. So, None was always
returned as a status.

Fix DB api function share_network_get_all_by_security_service - second param
should be named 'security_service_id' instead of 'share_network_id'.

Add unit and tempest tests.

Implements bp improve-share-network-list-filtering

Change-Id: I7c3e44068fb39672d1d6c9e06527fde2604672a9
Merge "Improve share-network list API filtering"