Add F2 screenshot functionality and image writing support

- 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/Windows64/KeyboardMouseInput.h

@@ -31,6 +31,7 @@ public:
 	static const int KEY_THIRD_PERSON = VK_F5;
 	static const int KEY_DEBUG_INFO = VK_F3;
 	static const int KEY_DEBUG_MENU = VK_F4;
+	static const int KEY_SCREENSHOT = VK_F2;
 
 	void Init();
 	void Tick();