Giveaway filtering

[akberenz]

Giveaways can be further filtered by query parameters (https://www.steamgifts.com/discussion/8SzdT/new-search-parameters-part-two ). Add dialog to sidebar allowing users to change these without needing to know the url content.

[akberenz]

Available filters currently include:

• dlc - boolean
• region_restricted - boolean
• copy_min - int, [1,∞)
• copy_max - int, [1,∞)
• level_min - int, [0,10]
• level_max - int, [0,10]
• entry_min - int, [0,∞)
• entry_max - int, [0,∞)
• release_date_min - date
• release_date_max - date
• metascore_min - int, [0,100]
• metascore_max - int, [0,100]

[akberenz]

61237e5f11bd8211686bec2d9695e83b261e377e