## Issue Addressed
#2293
## Proposed Changes
- Modify the handler for the `eth_chainId` RPC (i.e., `get_chain_id`) to explicitly match against the Geth error string returned for pre-EIP-155 synced Geth nodes
- ~~Add a new helper function, `rpc_error_msg`, to aid in the above point~~
- Refactor `response_result` into `response_result_or_error` and patch reliant RPC handlers accordingly (thanks to @pawanjay176)
## Additional Info
Geth, as of Pangaea Expanse (v1.10.0), returns an explicit error when it is not synced past the EIP-155 block (2675000). Previously, Geth simply returned a chain ID of 0 (which was obviously much easier to handle on Lighthouse's part).
Co-authored-by: Paul Hauner <paul@paulhauner.com>
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