inspector: convert event params to protocol without json

Event params object can be converted to inspector protocol directly.
This also enables binary data, like `Network.dataReceived`, to be sent
in the inspector protocol from JavaScript since JSON representation
does not support plain binary data.

Author: legendecas

lib/inspector.js

@@ -24,6 +24,7 @@ if (!hasInspector)
 
 const EventEmitter = require('events');
 const { queueMicrotask } = require('internal/process/task_queues');
+const { kEmptyObject } = require('internal/util');
 const {
   isUint32,
   validateFunction,
@@ -189,12 +190,10 @@ function inspectorWaitForDebugger() {
     throw new ERR_INSPECTOR_NOT_ACTIVE();
 }
 
-function broadcastToFrontend(eventName, params) {
+function broadcastToFrontend(eventName, params = kEmptyObject) {
   validateString(eventName, 'eventName');
-  if (params) {
-    validateObject(params, 'params');
-  }
-  emitProtocolEvent(eventName, JSONStringify(params ?? {}));
+  validateObject(params, 'params');
+  emitProtocolEvent(eventName, params);
 }
 
 const Network = {