Investigate changes needed for Capella in Web3Signer

[jframe]

For Capella CL updates, there’s new block bodies and blinded block bodies to cater for sending bls_to_execution changes and withdrawals.

• Identify changes for Web3Signer in terms of withdrawl signing requests (New API or modifications to existing API?).
• Coordinate with EL team (such as Teku) to finalize the changes
• Create new issues if required.

Timebox to 0.5 day

[james-prysm]

#673 might be a duplicate or related to this

[siladu]

When we update our Sepolia canaries, we should take this into account:

web3signer currently uses a cli option in playbooks that has been renamed from --Xmetrics-block-timing-tracking-enabled to --metrics-block-timing-tracking-enabled
recommend removing that cli arg from inventory prior to updating to the imminent 23.2.0 release which is about to be cut with Sepolia Capella configuration.