[WIP] Qt: Add config window controls (#655)

* Qt: Add config window controls

* Fix Windows build

* Fix audio slider

* Qt configs: Make thread-safe, properly update audio enable & renderdoc settings

* Qt configs: Add `connectCheckbox` function

* Qt configs: Add `connectCheckbox` function

* Rename spuLayout

* Add Discord RPC reloading

* Allow configuring the app icon

* Qt: Serialize icon & theme, properly set them

* Add rnap and rcow icons

* Qt: Fix forceShadergen config

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Co-authored-by: wheremyfoodat <44909372+wheremyfoodat@users.noreply.github.com>

include/frontend_settings.hpp

@@ -0,0 +1,32 @@
+#pragma once
+#include <string>
+
+// Some UI settings that aren't fully frontend-dependent. Note: Not all frontends will support the same settings.
+// Note: Any enums should ideally be ordered in the same order we want to show them in UI dropdown menus, so that we can cast indices to enums
+// directly.
+struct FrontendSettings {
+	enum class Theme : int {
+		System = 0,
+		Light = 1,
+		Dark = 2,
+		GreetingsCat = 3,
+		Cream = 4,
+	};
+
+	// Different panda-themed window icons
+	enum class WindowIcon : int {
+		Rpog = 0,
+		Rsyn = 1,
+		Rnap = 2,
+		Rcow = 3,
+	};
+
+	Theme theme = Theme::Dark;
+	WindowIcon icon = WindowIcon::Rpog;
+
+	static Theme themeFromString(std::string inString);
+	static const char* themeToString(Theme theme);
+
+	static WindowIcon iconFromString(std::string inString);
+	static const char* iconToString(WindowIcon icon);
+};