fix(logs): blocking a blocked user writes no row; one upload submit path

Follow-ups from the review of the audit log layers:

- Blocking a user who is already blocked, or unblocking one who is
  not, changes nothing and now writes no row, like any other edit
  that changes nothing.
- write_chunk takes the request instead of the user and an optional
  request; the view always had one, so the branch only tests used
  is gone and every chunk 0 goes through the same audited submit.
- Tests: a busy clone creates no job and its row carries the page's
  message; a later chunk that fails writes no submit row; libvirt
  refusing a network or pool delete is a failed row.

admin/tests/test_audit_rows.py

@@ -65,6 +65,8 @@ class UserRowTests(TestCase):
         carol = User.objects.get(username="carol")
         Logs.objects.all().delete()
         self.client.post(reverse("admin:user_block", args=[carol.pk]))
+        self.client.post(reverse("admin:user_block", args=[carol.pk]))  # already blocked: nothing changes
+        self.client.post(reverse("admin:user_unblock", args=[carol.pk]))
         self.client.post(reverse("admin:user_unblock", args=[carol.pk]))
         self.client.post(reverse("admin:user_update_password", args=[carol.pk]),
                          {"password1": "New-carol-pass-1", "password2": "New-carol-pass-1"})