Resolve "Clean up duplicated, not clear functionality in NetworkElement NBI server"

api/go/gosdn/networkelement/networkelement.pb.go

api/go/gosdn/networkelement/networkelement.pb.gw.go

api/go/gosdn/networkelement/networkelement_grpc.pb.go

api/openapiv2/gosdn_northbound.swagger.json

api/proto/buf.lock

api/proto/gosdn/networkelement/networkelement.proto

applications/arista-routing-engine/network-element.go

applications/basic-interface-monitoring/network-element.go

applications/hostname-checker/app.go

applications/venv-manager/venv-manager/venv-manager.go

cli/adapter/PndAdapter.go

controller/api/managedNetworkElement.go

controller/controller.go

controller/northbound/server/networkElement.go