Move shared Updater logic into UpdaterCommon

Source/Core/UpdaterCommon/UI.h

@@ -0,0 +1,26 @@
+// Copyright 2018 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <string>
+
+namespace UI
+{
+void MessageLoop();
+void Error(const std::string& text);
+void Stop();
+
+void SetDescription(const std::string& text);
+
+void SetTotalMarquee(bool marquee);
+void ResetTotalProgress();
+void SetTotalProgress(int current, int total);
+
+void SetCurrentMarquee(bool marquee);
+void ResetCurrentProgress();
+void SetCurrentProgress(int current, int total);
+
+void SetVisible(bool visible);
+}  // namespace UI