Improve performance of Versioning system on repositories

[trgiangdo]

Description

1. The _load_all() and _load_all_by() methods of FS repository is searching for the version inside file content, while previously this only need to look at the file name.
2. Every time a new entity is created, the latest version is retrieve from the version.json file. There should be another mechanism to store and load the latest version number from memory.

[trgiangdo]

On SQLrepo, _delete_by() method can be:

def _delete_by(self, attribute: str, value: str):
        self.db.query(self.model_type).filter_by(**{attribute: value}).delete()

Probably something similar on MongoRepo