config system rework

[mh-northlander]

current configuration system is a bit difficult to use: e.g. how the arguments of config::new(config_path, resource_dir, system_dict) interacts?

• let it align with Java version
  • add PathAnchor to resolve resource file paths
• embed default non-dictionary data to the binary
• for Python, sudachipy.Config should be the main class for the configuration

[eiennohito]

IMHO, Sudachi.rs does not need the PathAnchor functionality from Java because there is no classpath (albeit Python modules can serve as one). But I agree that in the current incarnation it is not clear how parameters interact.