add default_persistence_allowed

In addition set all config options in every test, as catch2 can run
tests out of order and as demonstrated in
e1ad60af4f this can be an issue

src/utils/is_requester_allowed_to_persist.hpp

@@ -19,7 +19,7 @@ namespace utils
  * 2. `persist_user_allowlist` contains the requester's jid
  * 3. `persist_user_denylist` contains the requester's domain
  * 4. `persist_user_allowlist` contains the contains the requester's domain
- * 5. allow
+ * 5. `default_persistence_allowed` is true (default true)
  */
 inline bool is_requester_allowed_to_persist(const Jid &requester) {
   // requester.bare checks
@@ -50,6 +50,6 @@ inline bool is_requester_allowed_to_persist(const Jid &requester) {
 
   // default allow
   // 5.
-  return true;
+  return Config::get_bool("default_persistence_allowed", true);
 }
 }