[Blazor] Cascading Parameter that transfers across render boundaries

This is a common point of confusion for customers, so we could add a new `SerializableCascadingValue` component or similar that is able to flow across component boundaries.

With the requirement that the value needs to be JSON serializable and that you won't (probably) get updates (it's a 1-time thing, but maybe we can update via enhanced navigations).

The internal component we use for the render boundary can capture the serializable value providers in the hierarchy, serialize those, and expose them once it begins rendering interactively.