Add `record_sampling_state` to `NDArray` backend

[lucianopaz]

Description

This feature request stems from this discussion. The idea is to add the ability to record and store the step methods' sampling_state to the NDArray backend. Potentially, also to also record it once sampling finishes.

The ZarrTrace backend development that gave birth to this idea used a link_stepper method to gain a reference to the step method and then get its sampling_state. This comment suggested adding the method to NDArray as well.