refactor: Move all commands to their own files (#4946)

src/controllers/commands/builtin/twitch/AddVIP.hpp

@@ -0,0 +1,16 @@
+#pragma once
+
+class QString;
+
+namespace chatterino {
+
+struct CommandContext;
+
+}  // namespace chatterino
+
+namespace chatterino::commands {
+
+/// /vip
+QString addVIP(const CommandContext &ctx);
+
+}  // namespace chatterino::commands