generate strong types for engine signals and connections

is there any interest in generating strong types for connections such as:

(this is probably a poor example, I'd need to dig in and make a PR to do it correctly)

```ts
declare module godot {
interface SceneTree implements MainLoop {
//overload 1 for network_peer_connected signal
function connect(
signal: "network_peer_connected",
target: T,
method: Extract | (...args: Parameters) => void, //could use e.g. MethodOf,
binds: Tail>,
flags: number = 0,
): number;
// more overloads, one per signal for discriminating union
}
}
```

该 issue 未指出文件、测试或类型生成入口点，仅提供了一个暂定示例。首先定位 Godot 引擎信号和连接当前的暴露方式，然后确定生成范围，并定义测试以验证代表性信号和连接所对应的 TypeScript 类型。

由索引模型根据 Issue 内容生成。