change: change log-query string value to bool

BREAKING CHANGE

As discussed on https://github.com/PostgREST/postgrest/issues/3934#issuecomment-3362806777,
this changes log-query to use a bool value, this:

- Simplifies config for users.
- Reduces effort in testing the different combinations.

Closes #3934

test/io/test_io.py

@@ -1013,7 +1013,7 @@ def test_log_query(level, defaultenv):
     env = {
         **defaultenv,
         "PGRST_LOG_LEVEL": level,
-        "PGRST_LOG_QUERY": "main-query",
+        "PGRST_LOG_QUERY": "true",
     }
 
     with run(env=env) as postgrest: