Merge devnet 3 (#2859)

## Issue Addressed

N/A

## Proposed Changes

Changes required for the `merge-devnet-3`. Added some more non substantive renames on top of @realbigsean 's commit. 
Note: this doesn't include the proposer boosting changes in kintsugi v3.

This devnet isn't running with the proposer boosting fork choice changes so if we are looking to merge https://github.com/sigp/lighthouse/pull/2822 into `unstable`, then I think we should just maintain this branch for the devnet temporarily. 


Co-authored-by: realbigsean <seananderson33@gmail.com>
Co-authored-by: Paul Hauner <paul@paulhauner.com>

consensus/types/src/execution_payload.rs

@@ -14,7 +14,7 @@ pub type Transaction<T> = VariableList<u8, T>;
 #[serde(bound = "T: EthSpec")]
 pub struct ExecutionPayload<T: EthSpec> {
     pub parent_hash: Hash256,
-    pub coinbase: Address,
+    pub fee_recipient: Address,
     pub state_root: Hash256,
     pub receipt_root: Hash256,
     #[serde(with = "ssz_types::serde_utils::hex_fixed_vec")]

consensus/types/src/execution_payload_header.rs

@@ -10,7 +10,7 @@ use tree_hash_derive::TreeHash;
 )]
 pub struct ExecutionPayloadHeader<T: EthSpec> {
     pub parent_hash: Hash256,
-    pub coinbase: Address,
+    pub fee_recipient: Address,
     pub state_root: Hash256,
     pub receipt_root: Hash256,
     #[serde(with = "ssz_types::serde_utils::hex_fixed_vec")]