This commit adds a new method called `write_event` to the `Database` class in `database.py`. The method takes an `Event` object as a parameter and adds it to the session before committing the changes to the database. This change simplifies the code in the `create_event` method by making use of the new `write_event` method.
The `write_event` method is used in the `Tracker` class in `tracker.py` to replace the call to `create_event`. This change improves the clarity and readability of the code.
Additionally, in the `Tracker` class, the `api` object is no longer created using `KeyDelivery.from_config`, as the `api` object is no longer referenced in the code. This change is made to remove unused code and improve code quality.
This commit also adds some new import statements to the `Tracker` class in `tracker.py` to support the new changes.
Lastly, two new tracker classes `KeyDelivery` and `PostAT` are added under the `trackers` directory. These new classes inherit from the `BaseTracker` class and implement the `get_status` method. The `KeyDelivery` class makes use of the `pykeydelivery.KeyDelivery` API to fetch tracking events, while the `PostAT` class uses the `postat.classes.api.PostAPI` API to fetch tracking events. The new tracker classes also define the supported carriers and their priorities.
Overall, these changes improve the functionality and structure of the codebase.
This commit adds new files for database and tracker classes. The database class includes methods for creating shipments, getting shipments, creating events, and getting shipment events. The tracker class includes methods for sending notifications, starting the tracking loop, and initializing the database and API.
