Debug: fix showing option name for list (vs. list content)

Debug: fix showing option name for list (vs. list content)

It's done in a hacky way (always was) and is fragile.
Turns out, too fragile to be good.
- some lists, we cannot match up to an option name
  eg. stderr/0002
- some, we're falling back to comparing the list content; this gets duplicates
  and thus gives incorrect info, which is worse than no info
  (we could scan for dups, I guess?)
  Why do we get dups when we're comparing the addrs of the string?
  - mmm, do we Really get dups?
    - Yes: same option across two routers. Must be a static init for a default.
      In which case, does it being a dup matter?
      - OK, we can check router_name / transport_name

Resulting testsuite sterr changes only partial, here.

There's a double check on local_parts in routers (always was).  Why?

One buildfarm animal (groundhog) is missing a "list element" line
possibly associated with dnssec_request_domains.  Why?