Feature: create a Backlog Game Roulette page

[NeiruBugz]

There is such thing as Steam Game Gauntlet that picks a random game from your Steam Library. Need to implement Game Roulette that picks a random game from the Backlog games list only.

• Roulette component
• Pick a random game and put it into "Playing" status
• Maybe, there is a need for filters for the platform. For example, user wants to pick a game from Nintendo backlog