refactor: Make all fetchers as an optional dependency group

+ Removing some dead code

scrapling/engines/_browsers/_camoufox.py

@@ -25,11 +25,11 @@ from scrapling.core._types import (
     Callable,
     SelectorWaitStates,
 )
-from scrapling.engines.toolbelt import (
+from scrapling.engines.toolbelt.convertor import (
     Response,
     ResponseFactory,
-    generate_convincing_referer,
 )
+from scrapling.engines.toolbelt.fingerprints import generate_convincing_referer
 
 __CF_PATTERN__ = re_compile("challenges.cloudflare.com/cdn-cgi/challenge-platform/.*")
 _UNSET = object()