Add Order Items and Order Item Options functionality

Add order item migration, empty models and seed data.

Create controller and routes.

Add show and index views. Validate those work.

Add order item options migration, model and db seed.

Add controller actions and routes.

Add order item options views. Validate all actions working.
Fix merge conflicts.
Merge pull request #12 from HollyM021980/HollyM021980-19718479943560_create_order_item_functionality

Holly m021980 19718479943560 create order item functionality