Continuation of #10851.

Implements EIP-7702 ("Set EOA Account Code") for pallet-revive: an EOA can sign an authorization designating a contract whose code runs on its behalf, while using the EOA's own storage and balance. See #9569 for background.

Changes

Pallet integration. eth_call now takes an authorization_list (Vec<AuthorizationListEntry>) and processes it before the call. List size is bounded by gas: each entry must be covered by worst_case_delegation_deposit(), and an empty list on a type-4 tx is rejected in into_call.

Updating the eth_call signature is safe — it's not dispatched directly by users, but is the inner call of eth_transact (signed by an Ethereum wallet, submitted via eth-rpc).

Authorization processing. process_authorizations validates each entry (chain ID, signature, nonce, account type), creates the authority account if needed, and sets/clears the delegation. Invalid entries are silently skipped per spec; the function is otherwise fallible (e.g. insufficient funds for an account's ED). Delegation changes are applied outside the call's transactional context, so they persist even if the call reverts.

Revive-specific cost. Per-authorization gas is higher than EVM: an entry may create a new account (needs ED), and delegating to a contract requires a code-lockup deposit plus a refcount bump on the code hash.

Storage. New AccountType::DelegatedEOA { delegate_target: Option<H160>, contract_info: ContractInfo<T> }:

• EOA → DelegatedEOA is permanent; clearing only sets delegate_target = None.
• Delegated EOAs get their own child trie keyed by the EOA's address; re-delegating preserves it.
• Code refcounts are incremented on set, decremented on clear.
• Clearing refunds the storage_base_deposit (code-lockup portion) but keeps the child trie and per-item accounting.

Execution.

• Callee is a delegated EOA → code loaded from the target, storage stays the EOA's.
• Constructors skip delegation lookup.
• No chain following: delegation is resolved at most once (A→B→C calling A runs B's code, not C's).

Benchmarks. process_new_account_authorization(n) (worst case) and process_existing_account_authorization(n) (best case, for weight refunds).

RPC. eth-rpc can submit and dry-run EIP-7702 txs; eth_getCode returns the 0xef0100 || address prefix for delegated EOAs.

Tests

• Validation: invalid chain_id / nonce skipped, chain_id 0 wildcard, contract accounts rejected, same-authority replay resolves to first valid entry.
• Lifecycle: set / update / clear, delegation resolution during calls, cleared delegations stop executing.
• Storage: re-delegation preserves storage across targets.
• Deposits: charges/refunds, re-delegation adjustments, refcount tracking, EOA→EOA charges nothing, multiple authorities each get their own deposit.
• Edge cases: chains not followed, SELFDESTRUCT preserves delegation, delegation to a nonexistent address is a no-op.
• RPC: end-to-end delegate → call → clear flow.