Revert "Use new onos-topo entity-relationship api (#1158)"

[shadansari]

This reverts commit d61b8e6.

[adibrastegarnia]

@shadansari
Great. Let me give it a try as well.

[shadansari]

unit tests (make test) passes but some integration tests fail even after the revert:

helmit test ./cmd/onos-config-tests -c ../onos-helm-charts --suite gnmi -n micro-onos

 --- FAIL: gnmi/TestCompactChanges (31.00s)
--- SKIP: gnmi/TestCreatedRemovedDevice (0.00s)
--- FAIL: gnmi/TestDeviceState (21.39s)
--- FAIL: gnmi/TestModels (12.51s)
    --- FAIL: gnmi/TestModels/Wrong_type (0.01s)
    --- FAIL: gnmi/TestModels/Unknown_path (0.02s)
    --- FAIL: gnmi/TestModels/Constraint_violation (0.02s)
    --- FAIL: gnmi/TestModels/Read_only_path (0.03s)
--- SKIP: gnmi/TestOfflineDevice (0.00s)
--- SKIP: gnmi/TestOfflineDeviceInTopo (0.00s)
--- SKIP: gnmi/TestOneLiveOneDeadDevice (0.00s)
--- FAIL: gnmi/TestSinglePath (10.59s)
--- FAIL: gnmi/TestSingleState (18.93s)
--- SKIP: gnmi/TestSubscribe (0.00s)
--- SKIP: gnmi/TestSubscribeOnce (0.00s)
--- FAIL: gnmi/TestSubscribeStateDiags (13.06s)
--- SKIP: gnmi/TestSubscribeStateGnmi (0.00s)
--- SKIP: gnmi/TestTransaction (0.00s)
--- FAIL: gnmi/TestTreePath (10.78s)
--- PASS: gnmi/TestUnreachableDevice (0.66s)
--- FAIL: gnmi/TestUpdateDelete (16.93s)