Refactor VB's Application Framework Network Class

The class [`Microsoft.VisualBasic.Devices.Network`](https://github.com/dotnet/winforms/blob/e47bebd2e1c8ce466f16ab0d40d0d7d60d5dcffa/src/Microsoft.VisualBasic.Forms/src/Microsoft/VisualBasic/Devices/Network.vb#L37), which is part of the Visual Basic Application Framework, is based on the obsoleted [`WebClient`](https://learn.microsoft.com/en-us/dotnet/api/system.net.webclient?view=net-7.0) class.

We need to modernize this part of the Application Framework to avoid breaking changes, should the `WebClient` class no longer be included in future versions of .NET.

This should be done in the .NET 9-time frame.

This also addresses https://github.com/dotnet/winforms/issues/3936.

Here is a potential general approach, which uses `HttpClient` instead of `WebClient`.
(!not tested, and my last Web-dev-experiences is quite a while, so, please double-check me here!)

```VB
Imports System.IO
Imports System.Net
Imports System.Net.Http

Public Class Network

Public Async Function DownloadFileWithCredentialsAndProgressAsAStartingPointAsync(
url As String,
destinationPath As String,
credentials As NetworkCredential,
progress As IProgress(Of Double)) As Task

Dim handler As New HttpClientHandler() With
{
.Credentials = credentials
}

Using httpClient As New HttpClient(handler)

Dim response = Await httpClient.GetAsync(url, HttpCompletionOption.ResponseHeadersRead)
Dim contentLength = response.Content.Headers.ContentLength

Using responseStream As Stream = Await response.Content.ReadAsStreamAsync()
Using fileStream As New FileStream(destinationPath, FileMode.Create, FileAccess.Write, FileShare.None)

Dim buffer(8191) As Byte
Dim totalBytesRead As Long = 0
Dim bytesRead As Integer

While (Await responseStream.ReadAsync(buffer, 0, buffer.Length)) > 0
Await fileStream.WriteAsync(buffer, 0, bytesRead)
totalBytesRead += bytesRead

If contentLength.HasValue Then
Dim percentage As Double = (CDbl(totalBytesRead) / CDbl(contentLength.Value)) * 100
progress.Report(percentage)
End If

End While
End Using
End Using
End Using
End Function
End Class
```