Add eth_call state overrides and eth_createAccessList support

[alisinabh]

• New :state_overrides option on Ethers.call/2 and Ethers.estimate_gas/2 to simulate against modified chain state (balances, nonces, code, storage slots)
• New Ethers.StateOverride module validating and encoding override sets into their JSON-RPC representation
• New Ethers.create_access_list/2 (+ bang variant) wrapping eth_createAccessList, returning the access list in the format transaction overrides accept so it can be fed straight back into send_transaction
• New optional RPC adapter callbacks (eth_call/4, eth_estimate_gas/4, eth_create_access_list/3) - custom adapters remain backwards compatible and get {:error, :state_overrides_not_supported} / {:error, :not_supported} when they do not implement them

[Copilot]

🟡 Not ready to approve

Batch usage for :create_access_list appears to be enabled by preprocessing but will send an unmapped RPC method name, leading to incorrect batch requests at runtime.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

This review doesn't count toward merge requirements. Sign up for the private preview to control whether Copilot approvals count.

Pull request overview

This PR extends the Ethers Elixir client with Ethereum simulation features: state overrides for eth_call / eth_estimateGas, plus eth_createAccessList support to generate EIP-2930 access lists that can be fed back into transactions.

Changes:

• Add :state_overrides to Ethers.call/2 and Ethers.estimate_gas/2, including optional RPC adapter callbacks for override-capable clients.
• Introduce Ethers.StateOverride for validating/encoding override sets into JSON-RPC format.
• Add Ethers.create_access_list/2 (+ bang variant) and decode the RPC result into the transaction-override-compatible access list format.

File summaries

File	Description
test/ethers/state_override_test.exs	Adds coverage for encoding and for call/estimate_gas behavior with state overrides.
test/ethers_test.exs	Adds tests for create_access_list/2 result shape and error behavior.
lib/ethers/state_override.ex	New module implementing validation + JSON-RPC encoding for state overrides.
lib/ethers/rpc_client/ethereumex_http_client.ex	Adds manual implementations for the new RPC calls not directly exposed by Ethereumex.
lib/ethers/rpc_client/adapter.ex	Extends the adapter behaviour with optional callbacks for overrides and access list creation.
lib/ethers.ex	Wires new options/APIs into the high-level client and adds post-processing for access list responses.
CHANGELOG.md	Documents the new features under Unreleased enhancements.

Review details

• Files reviewed: 7/7 changed files
• Comments generated: 3
• Review effort level: Low

We're testing this review assessment. Please use 👍 or 👎 to tell us if it's correct.

[Copilot]

🟢 Ready to approve

The implementation matches the PR description, preserves adapter backwards compatibility via optional callbacks and feature detection, and includes solid automated test coverage for the new behaviors.

This review doesn't count toward merge requirements. Sign up for the private preview to control whether Copilot approvals count.

Review details

• Files reviewed: 7/7 changed files
• Comments generated: 0 new
• Review effort level: Low

We're testing this review assessment. Please use 👍 or 👎 to tell us if it's correct.