Move CSFML source files to CSFML/ directory

This helps make it easier to distinguish SFML files from CSFML files.
This is especially important for CSFML private headers which are
often C++ code with .hpp file extensions. This change means SFML and
CSFML can use headers with the same name without conflict.

include/CSFML/Window.h

@@ -0,0 +1,43 @@
+////////////////////////////////////////////////////////////
+//
+// SFML - Simple and Fast Multimedia Library
+// Copyright (C) 2007-2023 Laurent Gomila (laurent@sfml-dev.org)
+//
+// This software is provided 'as-is', without any express or implied warranty.
+// In no event will the authors be held liable for any damages arising from the use of this software.
+//
+// Permission is granted to anyone to use this software for any purpose,
+// including commercial applications, and to alter it and redistribute it freely,
+// subject to the following restrictions:
+//
+// 1. The origin of this software must not be misrepresented;
+//    you must not claim that you wrote the original software.
+//    If you use this software in a product, an acknowledgment
+//    in the product documentation would be appreciated but is not required.
+//
+// 2. Altered source versions must be plainly marked as such,
+//    and must not be misrepresented as being the original software.
+//
+// 3. This notice may not be removed or altered from any source distribution.
+//
+////////////////////////////////////////////////////////////
+
+#pragma once
+
+////////////////////////////////////////////////////////////
+// Headers
+////////////////////////////////////////////////////////////
+
+#include <CSFML/System.h>
+#include <CSFML/Window/Clipboard.h>
+#include <CSFML/Window/Context.h>
+#include <CSFML/Window/Cursor.h>
+#include <CSFML/Window/Event.h>
+#include <CSFML/Window/Joystick.h>
+#include <CSFML/Window/JoystickIdentification.h>
+#include <CSFML/Window/Keyboard.h>
+#include <CSFML/Window/Mouse.h>
+#include <CSFML/Window/Sensor.h>
+#include <CSFML/Window/Touch.h>
+#include <CSFML/Window/VideoMode.h>
+#include <CSFML/Window/Window.h>