otNetDataDnsSrpServicePublisherCallback
Pointer type defines the callback used to notify when a "DNS/SRP Service" entry is added to or removed from the Thread Network Data. On remove the callback is invoked independent of whether the entry is removed by `Publisher` (e.g., when there are too many similar entries already present in the Network Data) or through an explicit call to unpublish the entry (i.e., a call to `otNetDataUnpublishDnsSrpService()`).