utils: add to_ascii helper (#33492)

passerelle/utils/conversion.py

@@ -63,3 +63,7 @@ def clean_string(string):
 def ensure_encoding(s, encoding):
     s = clean_string(s)
     return s.encode(encoding, 'replace').decode(encoding)
+
+
+def to_ascii(s):
+    return unidecode.unidecode(s).decode('ascii')