Deduplicate code in rpc::EVMExecutor and ExecutionProcessor

[canepat]

For historical reasons, the simulated block and transaction execution necessary to implement many relevant JSON-RPC API endpoints (e.g. eth_call, eth_estimateGas, trace_call, trace_block...) is captured in rpc::EVMExecutor class, which unfortunately contains quite a lot of duplicated code wrt ExecutionProcessor from core package.

We should investigate if it's feasible to merge these two abstraction into a single one.

See also #2284 (comment)