Get device model when adding a device

.gitignore

.golangci.yml

Makefile

controller/controller.go

controller/interfaces/device/device.go

controller/interfaces/southbound/sbi.go

controller/nucleus/databasePndStore.go

controller/nucleus/device.go

controller/nucleus/gnmi_transport.go

controller/nucleus/initialise_test.go

controller/nucleus/principalNetworkDomain.go

controller/nucleus/principalNetworkDomain_test.go

controller/nucleus/southbound.go

controller/test/plugin/gostructs.go

controller/test/yang/yang.go

csbi/Dockerfile

csbi/models/experimental/eos/models/arista-cli.yang

csbi/models/experimental/eos/models/arista-eos-types.yang

csbi/models/experimental/eos/models/arista-exp-eos.yang

...models/experimental/eos/models/cert/arista-gnoi-cert.yang