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/async_webcrawler.py

@@ -584,9 +584,9 @@ class AsyncWebCrawler:
 
         # Log processing completion
         self.logger.info(
-            message="Processed {url:.50}... | Time: {timing}ms",
+            message="{url:.50}... | Time: {timing}s",
             tag="SCRAPE",
-            params={"url": _url, "timing": int((time.perf_counter() - t1) * 1000)},
+            params={"url": _url, "timing": int((time.perf_counter() - t1) * 1000) / 1000},
         )
 
         ################################