Proposal: With block with variable declaration to allow local scope and object Ref

Combining this https://github.com/dotnet/vblang/issues/437#issuecomment-490632543 with this https://github.com/dotnet/vblang/issues/393
We can have a new local scope like this:
```VB.NET
If condition Then
Dim x = 1
End If

With X = "Test"
' This is a local scope to use X
End With

With X As Integer = 0
' This is a local scope to use X
End With

With X = Form1
' use X as a ref for Form1
X.Show()
` or use the . directly
.Hide()
End With

```