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 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()