Update to consensus-specs v1.1.9 (#3016)

## Issue Addressed

Closes #3014

## Proposed Changes

- Rename `receipt_root` to `receipts_root`
- Rename `execute_payload` to `notify_new_payload`
   - This is slightly weird since we modify everything except the actual HTTP call to the engine API. That change is expected to be implemented in #2985 (cc @ethDreamer)
- Enable "random" tests for Bellatrix.

## Notes

This will break *partially* compatibility with Kintusgi testnets in order to gain compatibility with [Kiln](https://hackmd.io/@n0ble/kiln-spec) testnets. I think it will only break the BN APIs due to the `receipts_root` change, however it might have some other effects too.

Co-authored-by: Michael Sproul <micsproul@gmail.com>

beacon_node/execution_layer/src/engine_api/json_structures.rs

@@ -89,7 +89,7 @@ impl<T: EthSpec> From<ExecutionPayload<T>> for JsonExecutionPayloadV1<T> {
             parent_hash,
             fee_recipient,
             state_root,
-            receipt_root,
+            receipts_root,
             logs_bloom,
             random,
             block_number,
@@ -106,7 +106,7 @@ impl<T: EthSpec> From<ExecutionPayload<T>> for JsonExecutionPayloadV1<T> {
             parent_hash,
             fee_recipient,
             state_root,
-            receipts_root: receipt_root,
+            receipts_root,
             logs_bloom,
             random,
             block_number,
@@ -145,7 +145,7 @@ impl<T: EthSpec> From<JsonExecutionPayloadV1<T>> for ExecutionPayload<T> {
             parent_hash,
             fee_recipient,
             state_root,
-            receipt_root: receipts_root,
+            receipts_root,
             logs_bloom,
             random,
             block_number,