refactor: deduplicate IRC parsing (#5678)

src/common/enums/MessageContext.hpp

@@ -0,0 +1,13 @@
+#pragma once
+
+namespace chatterino {
+
+/// Context of the message being added to a channel
+enum class MessageContext {
+    /// This message is the original
+    Original,
+    /// This message is a repost of a message that has already been added in a channel
+    Repost,
+};
+
+}  // namespace chatterino