Fixed passing share_server to teardown_network

Pass share_server backend_details to teardown network.
Removed calling db method share_server_get which raises
exception if share server does not exists with calling
method _get_share_server in delete_share.

Partially-implements bp implement-backend-details-in-drivers
Related-Bug #1332080

Change-Id: Id34c1b299f28d5e6050c481dce01b6f70d1be995
Merge "Fixed passing share_server to teardown_network"