Delete models. Models can be extracted from ygot code.

api/models/iana-if-type.yang

api/models/ietf-inet-types.yang

api/models/ietf-interfaces.yang

api/models/ietf-yang-types.yang

api/models/openconfig-acl.yang

api/models/openconfig-extensions.yang

api/models/openconfig-if-types.yang

api/models/openconfig-inet-types.yang

api/models/openconfig-interfaces.yang

api/models/openconfig-packet-match-types.yang

api/models/openconfig-packet-match.yang

api/models/openconfig-types.yang

api/models/openconfig-yang-types.yang