Exposes IP/FQDN in apisixRoutes status

### Description

As a end user i want to use external-dns project to manage my DNS records. I can use unstructured source for that (https://github.com/kubernetes-sigs/external-dns/blob/master/docs/sources/unstructured.md) but in apisixRoutes i'm lacking infos about where will need to point the DNS record so i must harcode it :-(

Start with the apisixRoutes status entry point and read the linked external-dns unstructured source documentation. Determine which external IP or FQDN information should be exposed for DNS records, then verify that the status contains the required target and that an external-dns unstructured source can consume it.

Written by the indexing model from the issue text.