Add F2 screenshot functionality (#1262)

- Updated `EControllerActions` to include `MINECRAFT_ACTION_SCREENSHOT`.
- Added conditional compilation for `stb_image_write.h` in `Minecraft.cpp`.
- Modified `run_middle()` to handle screenshot key press.
- Updated `tick()` to capture and save screenshots as PNG files.
- Introduced `KEY_SCREENSHOT` in `KeyboardMouseInput.h` mapped to F2.
- Added `stb_image_write.h` for image writing capabilities.

Minecraft.Client/Common/App_enums.h

@@ -878,7 +878,8 @@ enum EControllerActions
 	MINECRAFT_ACTION_SPAWN_CREEPER,
 	MINECRAFT_ACTION_CHANGE_SKIN,
 	MINECRAFT_ACTION_FLY_TOGGLE,
-	MINECRAFT_ACTION_RENDER_DEBUG
+	MINECRAFT_ACTION_RENDER_DEBUG,
+	MINECRAFT_ACTION_SCREENSHOT
 };
 
 enum eMCLang