Clean up Twitch badge appending code

src/providers/twitch/TwitchBadge.cpp

@@ -0,0 +1,31 @@
+#include "providers/twitch/TwitchBadge.hpp"
+
+#include <QSet>
+
+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> channelAuthority{"moderator", "vip", "broadcaster"};
+const QSet<QString> subBadges{"subscriber", "founder"};
+
+Badge::Badge(QString key, QString value)
+    : key_(std::move(key))
+    , value_(std::move(value))
+{
+    if (globalAuthority.contains(this->key_))
+    {
+        this->flag_ = MessageElementFlag::BadgeGlobalAuthority;
+    }
+    else if (channelAuthority.contains(this->key_))
+    {
+        this->flag_ = MessageElementFlag::BadgeChannelAuthority;
+    }
+    else if (subBadges.contains(this->key_))
+    {
+        this->flag_ = MessageElementFlag::BadgeSubscription;
+    }
+}
+
+}  // namespace chatterino