RPC call to view realm state

[thehowl]

We want a RPC call to view and inspect the state of a realm. Ideally, as per #1974, we want it to also be able to handle advanced use-cases like closures; but we can start off simple with primitive values and then grow from there.

This can allow us to eventually enable workflows like those mentioned in #2989, where after downloading a remote state into a local installation we can use it in gnodev and gno run|test, so that they can be pre-loaded with the remote state.

Related: #2949, #1776.