Close<Result> has been removed from IMvxNavigationService
## 🔙 Regression

<!--- Summary description of the regression --->
I've been using MvvmCross since version 7,  most I worked with was version 8, lately wanted to upgrade to version 9, what was strange for me was I noticed that I can't close the ViewModel with return of result like before, after I took a look at the source I saw only one (out of the two) versions of Close method remained and its : 

``` cs
Task<bool> Close(IMvxViewModel viewModel, CancellationToken cancellationToken = default);
```
however, the implementation still exists in MvxNavigationService

``` cs
public virtual async Task<bool> Close<TResult>(
            IMvxViewModelResult<TResult> viewModel, TResult result, CancellationToken cancellationToken = default)
```


### Old (and correct) behavior
Exists:
``` cs
public virtual async Task<bool> Close<TResult>(
            IMvxViewModelResult<TResult> viewModel, TResult result, CancellationToken cancellationToken = default)
```

### Current behavior
Not exists:
``` cs
public virtual async Task<bool> Close<TResult>(
            IMvxViewModelResult<TResult> viewModel, TResult result, CancellationToken cancellationToken = default)
```

### Reproduction steps
bring back the above method so we can't return the result from the closed ViewModel 

### Configuration

**Version:** 9.x

**Platform:** 
- [ ] :iphone: iOS
- [ ] :robot: Android
- [ ] :checkered_flag: WPF
- [ ] :earth_americas: UWP
- [ ] :apple: MacOS
- [ ] :tv: tvOS
- [ ] :monkey: Xamarin.Forms
