feat: add CancunPayloadFields for engine_newPayloadV3

[Rjected]

This introduces a struct for the extra fields introduced in engine_newPayloadV3, because these fields are provided together when engine_newPayloadV3 is called. Either they both exist, or are both None.

[codecov]

Codecov Report

Merging #4407 (c9fa0c0) into main (e576c00) will increase coverage by 0.00%.
The diff coverage is 56.25%.

Files Changed	Coverage Δ
crates/consensus/beacon/src/engine/message.rs	38.46% <ø> (ø)
crates/rpc/rpc-engine-api/src/engine_api.rs	80.46% <0.00%> (-0.47%)	⬇️
crates/rpc/rpc-types/src/eth/engine/cancun.rs	0.00% <0.00%> (ø)
crates/consensus/beacon/src/engine/mod.rs	75.16% <75.00%> (-0.26%)	⬇️
crates/consensus/beacon/src/engine/handle.rs	88.88% <100.00%> (-0.91%)	⬇️
crates/consensus/beacon/src/engine/test_utils.rs	77.49% <100.00%> (ø)

... and 7 files with indirect coverage changes

Flag	Coverage Δ
integration-tests	16.69% <12.50%> (-0.03%)	⬇️
unit-tests	63.78% <56.25%> (+0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Components	Coverage Δ
reth binary	29.21% <ø> (ø)
blockchain tree	83.52% <ø> (ø)
pipeline	90.25% <ø> (ø)
storage (db)	74.81% <ø> (ø)
trie	94.88% <ø> (ø)
txpool	48.79% <ø> (+0.49%)	⬆️
networking	77.46% <ø> (-0.07%)	⬇️
rpc	57.30% <0.00%> (-0.03%)	⬇️
consensus	63.52% <90.00%> (-0.14%)	⬇️
revm	31.74% <ø> (ø)
payload builder	6.37% <ø> (ø)
primitives	86.21% <ø> (ø)

[mattsse]

lgtm,

it's a bit weird that this a new argument and not additional fields, but we should just mirror that