Support `ValueTuple<string, object>` as state of scope.

[quabug]

It would be nice to code like logger.BeginScope(("propertyName", (object)property)) or even better with an extension public static IDisposable BeginScope(this ILogger logger, string name, object value).

[nblumhardt]

Definitely a syntactic improvement; the first variant would be the preferred one since consumers of this library don't normally want to depend on additional libraries to add things like the extra BeginScope overload.

Would be great if anyone watching along has the opportunity to explore this further/open a PR for discussion.

[sungam3r]

Can be closed?