nxos: merge nxapi/cli tests - vrf_interface, vrrp, vtp_domain, vtp_password, vtp_version, vtep (#28242)
* refactor nxos_vrf_interface
* refactor nxos_vrrp
* refactor nxos_vtp_domain
* refactor nxos_vtp_password
* refactor nxos_vtp_version
* refactor nxos_vxlan_vtep
