* MEV validator registration
* add nearby canary to detect new beacon chain forks
* remove special MEV graffiti
* web3signer support
* fix trace logging
* Nim 1.2 needs raises Defect
* use template rather than proc in REST JSON parsing
* use --payload-builder-enable and --payload-builder-url
* explicitly default MEV to disabled
* explicitly empty default value for payload builder URL
* revert attestation pool to unstable version