Move frontend-common to util/core

src/core/imgui_overlays.h

@@ -0,0 +1,28 @@
+// SPDX-FileCopyrightText: 2019-2022 Connor McLaughlin <stenzek@gmail.com>
+// SPDX-License-Identifier: (GPL-3.0 OR CC-BY-NC-ND-4.0)
+
+#pragma once
+
+#include "util/imgui_manager.h"
+
+namespace ImGuiManager {
+void RenderTextOverlays();
+void RenderOverlayWindows();
+}
+
+namespace SaveStateSelectorUI {
+
+static constexpr float DEFAULT_OPEN_TIME = 5.0f;
+
+void Open(float open_time = DEFAULT_OPEN_TIME);
+void RefreshList();
+void DestroyTextures();
+void Close(bool reset_slot = false);
+
+void SelectNextSlot();
+void SelectPreviousSlot();
+
+void LoadCurrentSlot();
+void SaveCurrentSlot();
+
+} // namespace SaveStateSelectorUI