Issue popularity filter does not calculate votes correctly
When sorting issues by popularity, filter does not calculate votes correctly.
What is the current bug behavior?
Issues are sorted using a total amount of upvotes or downvotes, without calculating overall popularity.
Issue with 30 upvotes and 4 downvotes should not be less popular than issue with 3 downvotes, 0 upvotes only.
What is the expected correct behavior?
Issues should be sorted by (upvotes - downvotes) number.