[desktop] More qt_common reorganization (#3916)

Ported from QML branch.

Main "big" change is that EmuThread is now a shared state in QtCommon,
not individually managed/passed around by GRenderWindow and MainWindow.

Signed-off-by: crueter <crueter@eden-emu.dev>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/3916
Reviewed-by: Lizzie <lizzie@eden-emu.dev>
Reviewed-by: MaranBr <maranbr@eden-emu.dev>

src/qt_common/qt_common.h

@@ -6,19 +6,31 @@
 
 #include <memory>
 #include <QWindow>
-#include <core/frontend/emu_window.h>
+
 #include "core/core.h"
 #include "core/file_sys/registered_cache.h"
+#include "core/frontend/emu_window.h"
 
-#include <core/file_sys/vfs/vfs_real.h>
+#include "qt_common/render/emu_thread.h"
+
+#include "core/file_sys/vfs/vfs_real.h"
+
+enum class StartGameType {
+    Normal, // Can use custom configuration
+    Global, // Only uses global configuration
+};
 
 namespace QtCommon {
 
+// TODO: Remove QWidget dependency
 extern QWidget* rootObject;
 
 extern std::unique_ptr<Core::System> system;
 extern std::shared_ptr<FileSys::RealVfsFilesystem> vfs;
 extern std::unique_ptr<FileSys::ManualContentProvider> provider;
+extern std::unique_ptr<EmuThread> emu_thread;
+
+extern const QStringList supported_file_extensions;
 
 typedef std::function<bool(std::size_t, std::size_t)> QtProgressCallback;
 
@@ -28,6 +40,9 @@ Core::Frontend::EmuWindow::WindowSystemInfo GetWindowSystemInfo(QWindow* window)
 
 void Init(QWidget* root);
 
+void SetupContentProviders();
+void SetupHID();
+
 const QString tr(const char* str);
 const QString tr(const std::string& str);