Add external identifiers for person, editable in edit form, with minimal features associated

src/Bundle/ChillPersonBundle/translations/messages+intl-icu.fr.yaml

@@ -21,6 +21,9 @@ accompanying_period:
             other {Participants}
         }
 
+    number: >-
+        n° {id}
+
 person:
     from_the: depuis le
     And himself: >-