Add Namespace statement

[RobertvanderHulst]

like in C# 10. All types following the namespace statement are automatically placed in that namespace.

NAMESPACE MyNamespace
CLASS Foo
END CLASS
DELEGATE MyDelegate

The class and the delegate will be automatically placed in the namespace Nested namespaces should be allowed

NAMESPACE Level1
NAMESPACE Level2 // declares Level1.Level2

In C# this is called File-scoped namespace declaration See https://docs.microsoft.com/en-us/dotnet/csharp/whats-new/csharp-10#file-scoped-namespace-declaration