fix:usr: Dump the active resolver fetches from dns_resolver_dumpfetches()

Previously, active resolver fetches were only dumped when the `fetches-per-zone` configuration option was enabled. Now, active resolver fetches are dumped along with the number of `clients-per-server` counters per resolver fetch.

Merge branch 'ondrej/make-dns_resolver_dumpfetches-dump-fetches' into 'main'

See merge request isc-projects/bind9!10107