Fix: If a product sku was updated and then deleted on the same day, it failed as the valid_till for the sku_version was set to yesterday while the valid_from was set to today.
Fix: Product update also failed as the db.commit was on the loop adding new skus
Fix: Also prevent creation of customer with blank phone number when adding a guest book.
Feature: Show the old bill of a customer in guest book
Fix: In reprint, allow changing of customer
Chore: Updated dependencies
Moved to sqlalchemy 2.0
Added type checking as much as possible
Updated angular to 15
Moved from Angular flex layout to tailwind css
Started developing on vscode with devcontainers
