#1375 : refactor(proxy) Deprecate 'proxy' parameter in BrowserConfig and enhance proxy string parsing

- Updated ProxyConfig.from_string to support multiple proxy formats, including URLs with credentials.
- Deprecated the 'proxy' parameter in BrowserConfig, replacing it with 'proxy_config' for better flexibility.
- Added warnings for deprecated usage and clarified behavior when both parameters are provided.
- Updated documentation and tests to reflect changes in proxy configuration handling.

tests/async/test_0.4.2_browser_manager.py

@@ -112,7 +112,7 @@ async def test_proxy_settings():
         headless=True,
         verbose=False,
         user_agent="Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36",
-        proxy="http://127.0.0.1:8080",  # Assuming local proxy server for test
+        proxy_config={"server": "http://127.0.0.1:8080"},  # Assuming local proxy server for test
         use_managed_browser=False,
         use_persistent_context=False,
     ) as crawler: