Add DNS api functions for LOC type

I noticed that the meta data for the LOC and DS functions was added by mistake ages ago in ecb8fc2c but no implementation.

While preparing a MR I noticed that DS functions are already proposed in #6187 (closed) so this one just for dns_loc_*

The error I got that triggered me: SoapFault: Method dns_ds_add does not exist in SoapClient->__call()