Causalgraph

Added
- utility function to get edge by cause and effect (get_edge_by_cause_and_effect())
- CausalPresenceIndex as part of causalgraph.owl Ontology -> successor of "hasConfidence"

Changed
- Removed unnecessary packages in requirements.txt and created seperate tests/requirements.txt
- Improved Performance and stability of get_name_and_object
- validation of properties now "False" as default
- Made usage of log_file_handler optional (default: False) = No log file will be created
- Move Status messageges for init to debug

Added

- In-Memory storage as default, eliminating SQL requirement:
- Previously, all causalgraph users were required to store data in a .sqlite database, which made fast (re-)creation of causalgraphs cumbersome.
- he underlying package, owlready2, does not have this storage requirement and can now be initialized to store everything in memory.
- Causalgraph users now have the option to choose "in-memory" storage as the default, with the storage in a SQL file being an alternative option.
- Improved Validation and Enhanced Clarity:
- Identified and addressed flaws in the general validation of properties, resulting in failing tests.
- Rewrote the function in `owlready2_utils.py` and incorporated the same functions for validation during the updating and creation of individuals.
- Validation now includes checking the domain and range for known properties, excluding max and minimum boundaries. Unknown properties will not be checked and will not raise exceptions.

Changed

- Enhanced usability py passing/returning entity objects:
- Revised certain functions in the causalgraph packag e to return the actual object (e.g. node, edge) instead just its name
- Improved usability by retrieving the object directly by default and allowing access to its name via `object.name`
- Bumped owlready2 version to 0.43

Fixed