WithParsed(async swallows exceptions

### Some examples of the use of WithParsed / WithParsedAsync with expected behavior
```
internal static class Program
{
private static void Main(string[] args)
{
Parser.Default.ParseArguments(args).WithParsed(_ => throw new Exception());
```
=> Unhandled exception. System.Exception: Exception of type 'System.Exception' was thrown.
As Expected.

```
internal static class Program
{
private static async Task Main(string[] args)
{
await Parser.Default.ParseArguments(args).WithParsedAsync(_ => throw new Exception());
```
=> Unhandled exception. System.Exception: Exception of type 'System.Exception' was thrown.
As Expected.

```
internal static class Program
{
private static async Task Main(string[] args)
{
await Parser.Default.ParseArguments(args).WithParsedAsync(async _ =>
{
await Task.CompletedTask; //just for demonstration
throw new Exception();
});
```
=> Unhandled exception. System.Exception: Exception of type 'System.Exception' was thrown.
As Expected.

### When using WithParsed with an async expresion in a synchrone context, it swallows the exception

```
internal static class Program
{
private static void Main(string[] args)
{
Parser.Default.ParseArguments(args).WithParsed(async _ =>
{
await Task.CompletedTask; //just for demonstration
throw new Exception();
});
```
=> Process finished with exit code 0.
Should also notify about Unhandled exception.

从 WithParsed 和 WithParsedAsync 入口点开始，使用 Parser.Default.ParseArguments 重现同步上下文示例。比较同步回调与传递给 WithParsed 的异步回调的行为。当异步回调中的异常不再被静默吞掉，并且该行为由回归测试覆盖时，即视为完成。

由索引模型根据 Issue 内容生成。