[Flight] Update stale blocked values in `createModelResolver` (#28669)

Alternative to #28620.

Instead of emitting lazy references to not-yet-emitted models in the
Flight Server, this fixes the observed issue in
https://github.com/unstubbable/ai-rsc-test/pull/1 by adjusting the lazy
model resolution in the Flight Client to update stale blocked root
models, before assigning them as chunk values. In addition, the element
props are not outlined anymore in the Flight Server to avoid having to
also handle their staleness in blocked elements.

fixes #28595