Add ability to hide Twitch Prediction badges (#2668)

We now properly categorize the Twitch `predictions` badges since they take up their own slot in Twitch web chat

src/providers/twitch/TwitchBadge.cpp

@@ -7,6 +7,7 @@ namespace chatterino {
 // set of badge IDs that should be given specific flags.
 // vanity flag is left out on purpose as it is our default flag
 const QSet<QString> globalAuthority{"staff", "admin", "global_mod"};
+const QSet<QString> predictions{"predictions"};
 const QSet<QString> channelAuthority{"moderator", "vip", "broadcaster"};
 const QSet<QString> subBadges{"subscriber", "founder"};
 
@@ -18,6 +19,10 @@ Badge::Badge(QString key, QString value)
     {
         this->flag_ = MessageElementFlag::BadgeGlobalAuthority;
     }
+    else if (predictions.contains(this->key_))
+    {
+        this->flag_ = MessageElementFlag::BadgePredictions;
+    }
     else if (channelAuthority.contains(this->key_))
     {
         this->flag_ = MessageElementFlag::BadgeChannelAuthority;