TODO removal

For each of these TODOs:

- If there's an active bug tracking the work, and the TODO provides
  something of value, I left it and standardized the formatting. I also
  added comments to the bug.

- If the comment provided no value (implement feature X when we do feature
  X), I deleted it with impunity.

- If the comment was stale (won't fix or just out of date), then we
  removed it uncerimoniously.

There was a single TODO that was actually actionable, so I enabled that
test.
I think it's better to have the full URL to the issue. That way if the issue is moved or the repo is relocated we always have a link to where it was. Also following the URL pattern enables us to add actionary TODO's, such as `// TODO: Remove filler code here once https://github.com/aspnet/SomeOtherRepo/issues/1234 is completed.`