VID-1627 Clean up VideosModuleController

We’re only returning videos from getWikiRelatedVideosTopics and
getStaffPicks, no need to do all that additional checking.
VID-1627 Delete unused method

getRelatedVideos essentially became a wrapper for
getWikiRelatedVideosTopics which didn’t do anything additionally. Get
rid of it and just use getWikiRelatedVideosTopics directly from the
controller.
VID-1627 Update js for VideosModule

We now accept a minimum of 3 videos, up to 5. Additionally, if there
are not enough wiki related videos, pull as many as needed from the
staff picks to try and hit that 5 video mark.
VID-1627 Updated unit test for videos module
VID-1627 CR changes
Merge pull request #3605 from Wikia/VID-1627

Vid 1627