[Proposal] initialize tuple items in place

Suppose I declared this Tuple at class level:
```VB.NET
ReadOnly StringConstants As (First As String, Second As String, Third As String) = ("One", "Two", "Three")
```

I think it is more readable to initialize each item in place like this:
```VB.NET
ReadOnly StringConstants As (
First As String = "One",
Second As String = "Two",
Third As String = "Three"
)
```

And it will be better if we use type inference. I know it is not allowed at class level, but I think tuple elements are local to the tuple, and don't belong to the class. I suggest to treat them as anonymous type elements are treated:

```VB.NET
ReadOnly StringConstants As (First = "One", Second = "Two", Third = "Three")
```

Note:
This syntax at class level will define StringConstants of type object
```VB.NET
ReadOnly StringConstants = (First := "One", Second := "Two", Third := "Three")
```

Start by reviewing the proposed tuple-initializer forms and the stated class-level type-inference behavior. No files, tests, or entry points are named; done would require settling the syntax and semantics as a Visual Basic language-design change.

Written by the indexing model from the issue text.