Replace is_limited filter with gacha_type

[LatidoReMe]

close #168

• Adds gacha_type filter, which functions similarly to /gacha's type filter
• Adds GACHA_TYPES to Gacha and called the gacha_type choices from there so we don't create the list twice for no reason
• Replaces is_limited cuteform with Gacha's gacha_type cuteform since the former isn't needed anymore
• 🎨 JS for is_limited was switched to work with gacha-type instead (https://github.com/MagiCircles/BanGDream-Static/pull/16)