Add a way to uninstall the wintun driver from the system

~~The installer should come with `wintun.dll` to be dropped in the same directory we will be downloading the VPN binary to. It should also install the driver during installation, and uninstall it during uninstallation. This could either be by delegating the install/uninstall to the Go code, or importing the DLL in the installer and calling the correct method.~~

~~We will most likely need to check-in `wintun.dll` to this repo.~~

We ship `wintun.dll` and it gets automatically loaded by the Go code, but we should add some method of uninstalling the system driver from the system on user request. Tailscale does this by having a signal you can send to the system service to have it uninstall the driver.

首先阅读自动加载 wintun.dll 的 Go 代码，以及负责驱动程序处理的系统服务入口点。将请求实现的用户触发卸载行为与 Tailscale 基于信号的方法进行比较；当用户请求可以向服务发送信号并安全地移除系统驱动程序时，即视为完成。

由索引模型根据 Issue 内容生成。