test: Rename wait_until_helper to wait_until_helper_internal

Co-authored-by: MarcoFalke <falke.marco@gmail.com>

test/functional/test_framework/util.py

@@ -241,7 +241,7 @@ def satoshi_round(amount):
     return Decimal(amount).quantize(Decimal('0.00000001'), rounding=ROUND_DOWN)
 
 
-def wait_until_helper(predicate, *, attempts=float('inf'), timeout=float('inf'), lock=None, timeout_factor=1.0):
+def wait_until_helper_internal(predicate, *, attempts=float('inf'), timeout=float('inf'), lock=None, timeout_factor=1.0):
     """Sleep until the predicate resolves to be True.
 
     Warning: Note that this method is not recommended to be used in tests as it is