Reorganize source files into logical subdirectories

Co-authored-by: Hirek193 <23196899+Hirek193@users.noreply.github.com>

application/scenarioloaderuilayer.h

@@ -0,0 +1,33 @@
+/*
+This Source Code Form is subject to the
+terms of the Mozilla Public License, v.
+2.0. If a copy of the MPL was not
+distributed with this file, You can
+obtain one at
+http://mozilla.org/MPL/2.0/.
+*/
+
+#pragma once
+
+#include "uilayer.h"
+#include "launcher/deferred_image.h"
+
+class scenarioloader_ui : public ui_layer {
+	int m_gradient_overlay_width;
+	int m_gradient_overlay_height;
+	GLuint m_gradient_overlay_tex;
+	deferred_image m_loading_wheel_frames[60];
+    std::vector<std::string> m_trivia;
+public:
+	scenarioloader_ui();
+	void render_() override;
+private:
+
+	/// <summary>
+	/// Loads random trivia from lang/trivia.json
+	/// and returns it as a vector of strings. Also performs background selection.
+	/// </summary>
+	std::vector<std::string> get_random_trivia();
+	void generate_gradient_tex();
+	void load_wheel_frames();
+};