HybridCache: richer detection for field-only types (ref STJ)

[mgravell]

HybridCache uses System.Text.Json for the default serializer, which has some opinions on fields; this means that named-tuples (or value-tuples generally), and types that use value tuples or otherwise field-only values, can lose data.

We already detect value-tuples specifically as the root type, but real-world usage has highlit wider ranges of scenarios. This PR adds deeper detection for this scenario, applying the same workaround. It duly considers collection types and recursion scenarios.

fix dotnet/aspnetcore#60934

Microsoft Reviewers: Open in CodeFlow

[mgravell]

Thought: we should explicitly restrict our override behaviour to scenarios that use the inbuilt STJ default options instance, not just ones that don't handle fields. If someone uses their own STJ options: we should respect it. The mechanism for people to do this is new and non-disclosed, so there is no issue changing that behaviour, i.e. right now the number of times anyone will have ever supplied a non-default STJ options is zero or a rounding error asymptotically approaching zero.