turning a lot of includes into forward declares

src/widgets/dialogs/LogsPopup.hpp

@@ -1,6 +1,5 @@
 #pragma once
 
-#include "common/Channel.hpp"
 #include "widgets/BaseWindow.hpp"
 
 namespace chatterino {
@@ -8,6 +7,12 @@ namespace chatterino {
 class Channel;
 class ChannelView;
 
+class Channel;
+using ChannelPtr = std::shared_ptr<Channel>;
+
+struct Message;
+using MessagePtr = std::shared_ptr<const Message>;
+
 class LogsPopup : public BaseWindow
 {
 public:
@@ -17,7 +22,7 @@ public:
 
 private:
     ChannelView *channelView_ = nullptr;
-    ChannelPtr channel_ = Channel::getEmpty();
+    ChannelPtr channel_;
 
     QString userName_;
     int roomID_;