Originally in 964da21817
we hid the SMTPAuthenticationError message except in
very specific cases. However this message often contains
helpful information from the mail provider, for example
here is a response from Office365:
> 535 5.7.139 Authentication unsuccessful, user is locked by your
organization's security defaults policy. Contact your administrator.
So, we will show the error message in the modal UI instead
of supressing it with a generic message to be more helpful.
This PR introduces a basic AdminNotice model to store these notices. Admin notices are categorized by their source/type (currently only notices from problem check.) They also have a priority.
In AdminDashboardData we have a bunch of problem checks implemented as methods on that class. This PR absolves it of the responsibility by promoting each of those checks to a first class ProblemCheck. This way each of them can have their own priority and arbitrary functionality can be isolated in its own class.
Think "extract class" refactoring over and over. Since they were all moved we can also get rid of the @@problem_syms class variable which was basically the old version of the registry now replaced by ProblemCheck.realtime.
In addition AdminDashboardData::Problem value object has been entirely replaced with the new ProblemCheck::Problem (with compatible API).
Lastly, I added some RSpec matchers to simplify testing of problem checks and provide helpful error messages when assertions fail.
There are a couple of reasons for this.
The first one is practical, and related to eager loading. Since /lib is not eager loaded, when the application boots, ProblemCheck["identifier"] will be nil because the child classes aren't loaded.
The second one is more conceptual. There turns out to be a lot of inter-dependencies between the part of the problem check system that live in /app and the parts that live in /lib, which probably suggests it should all go in /app.
