CodeWriter Invoke methode

Currently when we want to Invoke something in a method body we have to use AppendLine:

```
methodBuilder.WithBody((x) =>
{
x.AppendLine($"await Test(argument1, argument2));
});
```
Idea would be to create an "InvocationBuilder" which we could use like this:

`x.Invoke(useAwait, methodname, params, prefix, suffix);`

When interested i would volunteer to create a PR.