Kiln mev boost (#3062)

## Issue Addressed

MEV boost compatibility

## Proposed Changes

See #2987

## Additional Info

This is blocked on the stabilization of a couple specs, [here](https://github.com/ethereum/beacon-APIs/pull/194) and [here](https://github.com/flashbots/mev-boost/pull/20).

Additional TODO's and outstanding questions

- [ ] MEV boost JWT Auth
- [ ] Will `builder_proposeBlindedBlock` return the revealed payload for the BN to propogate
- [ ] Should we remove `private-tx-proposals` flag and communicate BN <> VC with blinded blocks by default once these endpoints enter the beacon-API's repo? This simplifies merge transition logic. 

Co-authored-by: realbigsean <seananderson33@gmail.com>
Co-authored-by: realbigsean <sean@sigmaprime.io>

consensus/state_processing/src/per_block_processing/process_operations.rs

@@ -8,9 +8,9 @@ use crate::VerifySignatures;
 use safe_arith::SafeArith;
 use types::consts::altair::{PARTICIPATION_FLAG_WEIGHTS, PROPOSER_WEIGHT, WEIGHT_DENOMINATOR};
 
-pub fn process_operations<'a, T: EthSpec>(
+pub fn process_operations<'a, T: EthSpec, Payload: ExecPayload<T>>(
     state: &mut BeaconState<T>,
-    block_body: BeaconBlockBodyRef<'a, T>,
+    block_body: BeaconBlockBodyRef<'a, T, Payload>,
     proposer_index: u64,
     verify_signatures: VerifySignatures,
     spec: &ChainSpec,
@@ -217,9 +217,9 @@ pub fn process_attester_slashings<T: EthSpec>(
 }
 /// Wrapper function to handle calling the correct version of `process_attestations` based on
 /// the fork.
-pub fn process_attestations<'a, T: EthSpec>(
+pub fn process_attestations<'a, T: EthSpec, Payload: ExecPayload<T>>(
     state: &mut BeaconState<T>,
-    block_body: BeaconBlockBodyRef<'a, T>,
+    block_body: BeaconBlockBodyRef<'a, T, Payload>,
     proposer_index: u64,
     verify_signatures: VerifySignatures,
     spec: &ChainSpec,