feat(browser): add standalone CDP browser launch and lxml extraction strategy

Add new features to enhance browser automation and HTML extraction:
- Add CDP browser launch capability with customizable ports and profiles
- Implement JsonLxmlExtractionStrategy for faster HTML parsing
- Add CLI command 'crwl cdp' for launching standalone CDP browsers
- Support connecting to external CDP browsers via URL
- Optimize selector caching and context-sensitive queries

BREAKING CHANGE: LLMConfig import path changed from crawl4ai.types to crawl4ai

tests/test_web_crawler.py

@@ -1,5 +1,5 @@
 import unittest, os
-from crawl4ai.types import LLMConfig
+from crawl4ai import LLMConfig
 from crawl4ai.web_crawler import WebCrawler
 from crawl4ai.chunking_strategy import (
     RegexChunking,