Odoo 14 Simple Progect: Purchase Lists

Create a new module Purchase Lists with two tables, header and related lines.
Header table will have the following fields
- code initialized from serial numbers
- description
- date
- user
- status (open, closed)

The Purchase List Lines will have following fields:
- Item No.
- Item Description
- Vendor No. (blank, user will choose it)
- Vendor Name (calculated from vendor no.)
- Quantity
- Unit price
- Amount (calculated as Quantity * Unit Price)

One Purchase List can have the same Item No. in many lines.
User can add or delete lines.

At the end of the Purchase List editing, the user will press an action "Confirm List" and that will create the actual Odoo Purchase Orders, one per Vendor No. with the related lines and information derived from the Purchase List.

The status will be changed to closed and the Purchase List will become not editable.

The purchase orders creaded will have a field with the relation to the Purchase List that created them.