Multiple bug fixes:

- `common` > `tests` > `InMemoryObjectDatabase.py`: enhance log error reporting
- `common` > `tools` > `descriptor` > `Tools.py`: correct formatting of non-string resource_values in custom config rules in method `format_custom_config_rules()`
- `common` > `tools` > `service` > `GenericRestServer.py`: correct format of reported listen URL