Add a NetLog event for HostResolverInternalResults extraction

Existing events only record the final synthesized HostCache::Entries.
Having a separate event per DNS response is helpful, especially
when we try to make connection attempts without waiting for all
responses.

Also rename existing events from HOST_RESOLVER_MANAGER_DNS_TASK_*
to HOST_RESOLVER_DNS_TASK for consistency.

Bug: chromium:1520720

Change-Id: I9f7075d993d5e92784bbf4d6f274f5a679308238
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5225064
Reviewed-by: Adam Rice <ricea@chromium.org>
Commit-Queue: Kenichi Ishibashi <bashi@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1250689}