Initial Ordering implementation

[PaulJWright]

This MR addresses an initial attempt at:

1. Database Setup: SQLite database using alembic for migrations. SQLite was selected for its simplicity and portability, as it enables a single-file database (data/orders.db), well-suited for Docker environments with volume mounting.

2. GET Endpoint for Orders: GET endpoint to read orders from the database and provide the results through an API. This endpoint is consumed by a Streamlit app to display order data (see screenshots below).

3. POST endpoint for creating orders. Note that this will need future updates to handle stock management. The Streamlit app was updated to display orders in a table format.

This is designed using an OrdersService to handle the Business logic, and uses a Repository Pattern (OrdersRepository) a UnitOfWork to handle interaction with the database.

# weird_salads.api.app
def get_orders():
    with UnitOfWork() as unit_of_work:
        repo = OrdersRepository(unit_of_work.session)
        orders_service = OrdersService(repo)
        results = orders_service.list_orders()
    return {"orders": [result.dict() for result in results]}

where the OrdersRepository directly queries the DB through the sqlalchemy model, OrderModel. For example, the OrdersRepository has the the list method that queries the OrderModel, and returns as a list of Order objects (Order is a class to hold the data).

# weird_salads.orders.repository.orders_repository
class OrdersRepository:
    def __init__(self, session):
        self.session = session

    def add(self, item):
        pass

    def _get(self, id: str):
        pass

    def get(self, id):
        pass
       
    def list(self):
        query = self.session.query(OrderModel)
        records = query.all()
        return [Order(**record.dict()) for record in records]
        
    def update(self, id):
        pass

    def delete(self, id):
        pass

and is accessed through the OrdersService from the get_order method:

class OrdersService:
    def __init__(self, orders_repository: OrdersRepository):
        self.orders_repository = orders_repository

    def place_order(self, item):
        pass

    def get_order(self, order_id: str):
        pass

    def list_orders(self):
        """
        get all orders
        """
        return self.orders_repository.list()