This changes the query to use a COUNT nested in an INNER JOIN, instead
of a COUNT plus a GROUP BY. There are two reasons for this:
1. Using a COUNT in an INNER JOIN can be quite a bit faster.
2. The use of a GROUP BY means that method calls such as "any?"
(and everything else that calls "count") operate on a Hash that
counts the amount of notes on a per project basis, instead of just
counting the total amount of projects.
The query has been moved into Project.trending as its logic is simple
enough. As a result of this testing the TrendingProjectsFinder class
simply involves testing if the right methods are called, removing the
need for setting up database records.
This groups milestones by title for issue views like it has been done for
the milestone dashboard/project overview. Before milestones with the
same title would show up multiple times in the filter dropdown and one could
only filter per project and milestone. Now the milestone filter is based
on the title of the milestone, i.e. all issues marked with the same
milestone title are shown.
