core/core: Replace includes with forward declarations where applicable

The follow-up to e2457418da, which
replaces most of the includes in the core header with forward declarations.

This makes it so that if any of the headers the core header was
previously including change, then no one will need to rebuild the bulk
of the core, due to core.h being quite a prevalent inclusion.

This should make turnaround for changes much faster for developers.

src/yuzu/game_list_p.h

@@ -18,10 +18,15 @@
 #include <QString>
 #include "common/logging/log.h"
 #include "common/string_util.h"
-#include "core/file_sys/content_archive.h"
-#include "ui_settings.h"
+#include "yuzu/ui_settings.h"
 #include "yuzu/util/util.h"
 
+namespace FileSys {
+class NCA;
+class RegisteredCache;
+class VfsFilesystem;
+} // namespace FileSys
+
 /**
  * Gets the default icon (for games without valid SMDH)
  * @param large If true, returns large icon (48x48), otherwise returns small icon (24x24)
@@ -196,10 +201,9 @@ class GameListWorker : public QObject, public QRunnable {
 
 public:
     GameListWorker(
-        FileSys::VirtualFilesystem vfs, QString dir_path, bool deep_scan,
-        const std::unordered_map<std::string, std::pair<QString, QString>>& compatibility_list)
-        : vfs(std::move(vfs)), dir_path(std::move(dir_path)), deep_scan(deep_scan),
-          compatibility_list(compatibility_list) {}
+        std::shared_ptr<FileSys::VfsFilesystem> vfs, QString dir_path, bool deep_scan,
+        const std::unordered_map<std::string, std::pair<QString, QString>>& compatibility_list);
+    ~GameListWorker() override;
 
 public slots:
     /// Starts the processing of directory tree information.
@@ -222,7 +226,7 @@ signals:
     void Finished(QStringList watch_list);
 
 private:
-    FileSys::VirtualFilesystem vfs;
+    std::shared_ptr<FileSys::VfsFilesystem> vfs;
     std::map<u64, std::shared_ptr<FileSys::NCA>> nca_control_map;
     QStringList watch_list;
     QString dir_path;