First Beta release

Included:

• BaseDocument (dict-like class with additional logic to work with MongoDB drivers);
• BaseDBManager, based on Motor Database, Collection, Client classes;
• BaseRepository, based on Motor Collection operations;
• BaseDBModel (with BaseCreatedUpdatedModel), based on pydantic.BaseModel;
• BaseSchema (with CreatedUpdatedBaseSchema), based on pydantic.BaseModel;
• BaseConfiguration (pydantic.Config);
• DBSessionMiddleware, based on BaseHTTPMiddleware;
• DBSession, fastapi.Depends ready class;
• OID (ObjectId), defined as custom pydantic type;
• PyCharmDebugLogger (development logger with source links to files);

In development:

• BaseActiveRecord, DB operations for one record (document);
• BaseDataMapper, DB operations based on BaseDBModel;