Add Products screen and ability to add / edit products

[wdziemia]

Work is being done in: feature/products_edit

Prelim work is being done in feature/products_edit. This work would require use register.json as a seed file for a database.

• Since we store a product receipts, what happens when a product is edited?

• Solution: Clone the product and mark as active and the source product is marked inactive. This will allow us to query for previous products (e.g. viewing the receipts). This has the added benefit to play nice with receipts once they are moved from strings into database entries. They are currently stored as strings in shared-prefs.