This code was introduced in commit 722a431b, but it stopped being used
in commit 7657a0e0.
The spec was failing sometimes because the method didn't order the
records, but the spec checked the records returned in a certain order.
Furthermore, the method `page` generated a potential conflict with
kaminari's `page method.
We need to add an ORDER BY clause; not doing so was causing different
processes to show up sometimes. As mentioned in the PostgreSQL manual:
> Because the order of the rows in the database table is unpredictable,
> when you use the LIMIT clause, you should always use the ORDER BY
> clause to control the order of rows. If you don’t do so, you will get
> an unpredictable result set.
The condition `params[:page_id] != 0` didn't work properly when editing
the homepage because in that case the parameter was `nil`, and the line
`SiteCustomization::Page.find(@card.site_customization_page_id)` raised
an exception because it couldn't find a page with a `nil` ID.
Fixing the issue while maintaining the check against `0` lead to complex
code, and so allowing `nil` in the database and assuming cards with no
`site_customization_page_id` belonged in the homepage seemed to be the
easiest solution.
Note there is some funkiness going on with class loadings
Had to create a `feed` and `widget_feed` table even though in this
first version the Widget::Feed includes only uses ActiveModel instead
of ActiveRecord, otherwise some specs failed
We’ll figure it out and clean up 😌
