update JSON string encodings in author directory

The following characters are no longer encoded
and are represented as themselves:

- & is no longer encoded
- / is no longer encoded
- < is no longer encoded
- > is no longer encoded
- [\x80-\xff] is no longer encoded

The author ID JSON files under `/author` have
been updated accordingly.

author/Anton_Algmyr.json

@@ -2,7 +2,7 @@
     "no_comment" : "mandatory comment: because comments were removed from the original JSON spec",
     "author_JSON_format_version" : "1.0 2023-06-10",
     "author_handle" : "Anton_Algmyr",
-    "full_name" : "Anton \u00c3\u0084lgmyr",
+    "full_name" : "Anton Älgmyr",
     "sort_word" : "algmyr",
     "location_code" : "SE",
     "location_name" : "Sweden",