Create SMS routing data

Creates SMS routing data for the specified SMS routing entry. Will only create data if the requested SMS routing entry belongs to the logged in organisation. The following properties may be set in the JSON body: * `operator` - the operator that will be routed via this entry * `smpp_bind` - the SMPP bind used for the route * `gt_config` - can only be updated by Master organisation, MNOs get default NULL * `msisdn_pool` - can only be updated by Master organisation, MNOs get default NULL * `country` - the country that will be routed via this entry * `sccp_called_party_prefix` - can only be updated by Master organisation, MNOs get default NULL **Notes:** * Either a `gt_config` OR an `smpp_bind` needs to be set. It is not possible to set both. * Either a `country` OR an `operator` needs to be set. It is not possible to set both. * If the `country` is set, the `operator` will be automatically set to `ANY`. * If the `operator` is set, the `country` will be automatically set to the operator's country.