feat(browser): add BrowserProfiler class for identity-based browsing

Adds a new BrowserProfiler class that provides comprehensive management of browser profiles for identity-based crawling. Features include:
- Interactive profile creation and management
- Profile listing, retrieval, and deletion
- Guided console interface
- Migration of profile management from ManagedBrowser
- New example script for identity-based browsing

ALSO:
- Updates logging format in AsyncWebCrawler
- Removes content filter from hello_world example
- Relaxes httpx version constraint

BREAKING CHANGE: Profile management methods from ManagedBrowser are now deprecated and delegate to BrowserProfiler

crawl4ai/__init__.py

@@ -42,6 +42,7 @@ from .async_dispatcher import (
 )
 from .docker_client import Crawl4aiDockerClient
 from .hub import CrawlerHub
+from .browser_profiler import BrowserProfiler
 from .deep_crawling import (
     DeepCrawlStrategy,
     BFSDeepCrawlStrategy,
@@ -66,6 +67,7 @@ __all__ = [
     "AsyncLoggerBase",
     "AsyncLogger",
     "AsyncWebCrawler",
+    "BrowserProfiler",
     "DeepCrawlStrategy",
     "BFSDeepCrawlStrategy",
     "BestFirstCrawlingStrategy",