Include fact check request recipients in note

Refactor led to a regression where if a user provided a comment along
with a fact check request, the email addresses wouldn’t be displayed.

* Show both comment and email addresses
* Include test to document behaviour
* Format mailto address to remove spaces, a mailto which contains
spaces is an invalid link
Merge pull request #298 from alphagov/fix-action-fact-check

Include fact check request recipients in note