Retry runtime calls if the proof is invalid

[tomaka]

(not finished, opening as a draft to pick it up later)

We have so-called "call proofs": we ask a node to execute a runtime function and build up a Merkle proof of all the storage values that are accessed during this call.
The proof is then sent back, and the executes the runtime function locally, using the proof in order to "replay" the storage accesses.

What the code currently doesn't handle is the situation where the peer has sent us an incomplete proof, where some storage values are missing. If that happens, we just fail the call altogether, while in reality we should consider that the peer is malicious and retry the request with a different peer.

[mergify]

Automatically approving tomaka's pull requests. This auto-approval will be removed once more maintainers are active.

[github-actions]

twiggy diff report

Difference in .wasm size before and after this pull request.

---

 Delta Bytes │ Item
─────────────┼──────────────────────────────────────────────────────────────────────────────────────────────────────
       +6225 ┊ <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll::h92fde01c47057b70
       -6220 ┊ <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll::hbda3c90fbca11f60
       -5029 ┊ <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll::he9fbacfdaef179eb
       -4798 ┊ <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll::ha1114a14b8133b39
       -4674 ┊ <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll::h0b58c6c1308f460c
       -4647 ┊ <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll::h80d91430cbe6b21a
       +3926 ┊ <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll::h1d0c8e0bd6c40363
       -3892 ┊ <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll::h3152e1f316e99983
       +3828 ┊ <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll::h9a7ee62eba5423cf
       +3813 ┊ <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll::h02773eab663c1e7b
       +3692 ┊ <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll::haa851e7aca74a297
       +2969 ┊ <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll::h448fa5f2e7939094
       -1694 ┊ smoldot::transactions::validate::validate_transaction::h2dcb91928e6619df
       +1595 ┊ smoldot::transactions::validate::validate_transaction::h31d228f2c2680543
       +1299 ┊ <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll::h92491bd8b5e70fed
       -1283 ┊ smoldot_light_base::runtime_service::RuntimeCallLock::storage_prefix_keys_ordered::h2e43c5271ef3dd75
       +1283 ┊ smoldot_light_base::runtime_service::RuntimeCallLock::storage_prefix_keys_ordered::h5ba49961e125a8b9
       +1256 ┊ <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll::habad09639da9ef00
       -1239 ┊ <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll::h1c008a9acc30701f
       +1213 ┊ <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll::h5c8e59261f6efd0f
        +530 ┊ ... and 67 more.
        -472 ┊ Σ [87 Total Rows]