Skip missing Cancun bits for non Eth mainnet chains

[Nashtare]

closes #562

Includes:

• skipping missing header fields
• updating decoder processing for pre-state execution (for now only beacon roots, feature gated to eth_mainnet)
• add safeguards on all crates for conflicting features
• have the trace_decoder directly take the burn_address from the data provided by the rpc module (for cdk_erigon feature)

Tested against a Polygon PoS RPC endpoint provided by @praetoriansentry and I managed to generate witness payloads with the rpc binary.

[Nashtare]

The removal of trace_decoder/src/decoding.rs is to fix a merge issue missed in #551. It was initially removed in #583.