The method getNewUserBody() was never designed for a list controller.
The method was just orphan. Now, instead, it's non-orphan, and it works
as expected.
This bug was highlighted by Andre Klapper, since their linter was screaming
about inconsistences in the current nonsense usage of getNewUserBody():
The code was just moved from the list controller, to the search engine.
- PhabricatorDashboardPanelListController (from)
- PhabricatorDashboardPanelSearchEngine (to)
Bonus point:
Adjusted the icon and the title to talk about "Panels" and not "Dashboards".
Added also some inline documentation with an hint about ?nux=1.
So now we can easily remember how to test this kind of things.
Closes T15844