expand solr query escape flow to include single quotes (#7931)

Author: JaydenTeoh

openlibrary/solr/query_utils.py

@@ -131,10 +131,12 @@ def fully_escape_query(query: str) -> str:
     'x\\\\:\\\\[A TO Z\\\\}'
     >>> fully_escape_query('foo AND bar')
     'foo and bar'
+    >>> fully_escape_query("foo's bar")
+    "foo\\\\'s bar"
     """
     escaped = query
     # Escape special characters
-    escaped = re.sub(r'[\[\]\(\)\{\}:"\-+?~^/\\,]', r'\\\g<0>', escaped)
+    escaped = re.sub(r'[\[\]\(\)\{\}:"\-+?~^/\\,\']', r'\\\g<0>', escaped)
     # Remove boolean operators by making them lowercase
     escaped = re.sub(r'AND|OR|NOT', lambda _1: _1.group(0).lower(), escaped)
     return escaped