Rename *_blob_count to *_blobs_per_block

Author: jtraglia

specs/electra/fork-choice.md

@@ -33,6 +33,6 @@ class PayloadAttributes(object):
     suggested_fee_recipient: ExecutionAddress
     withdrawals: Sequence[Withdrawal]
     parent_beacon_block_root: Root
-    target_blob_count: uint64  # [New in Electra]
-    maximum_blob_count: uint64  # [New in Electra]
+    target_blobs_per_block: uint64  # [New in Electra:EIP7742]
+    maximum_blobs_per_block: uint64  # [New in Electra:EIP7742]
 ```

specs/electra/validator.md

@@ -176,8 +176,8 @@ def prepare_execution_payload(state: BeaconState,
         suggested_fee_recipient=suggested_fee_recipient,
         withdrawals=withdrawals,
         parent_beacon_block_root=hash_tree_root(state.latest_block_header),
-        target_blob_count=MAX_BLOBS_PER_BLOCK // 2,  # [New in Electra]
-        maximum_blob_count=MAX_BLOBS_PER_BLOCK,  # [New in Electra]
+        target_blobs_per_block=MAX_BLOBS_PER_BLOCK // 2,  # [New in Electra:EIP7742]
+        maximum_blobs_per_block=MAX_BLOBS_PER_BLOCK,  # [New in Electra:EIP7742]
     )
     return execution_engine.notify_forkchoice_updated(
         head_block_hash=parent_hash,