Allow jumping into product edit from receipt addition

[teolemon]

Problem

• It might happen that products are unknown in receipt addition, because they are on OPF, OPFF, OBF, or because they simply don't exist
• It might happen that the photo seems outdated when adding the product.

Proposed solution

• Allow clicking on the photo or placeholder of the product to jump into a product mode that allows either editing the product or if it does not exist select a target project, and then proceed to product addition.

[monsieurtanuki]

Allow clicking on the photo or placeholder of the product to jump into a product mode that allows either editing the product or if it does not exist select a target project, and then proceed to product addition.

For the record the prices are added only when the user clicks on the "send the prices" button.
Therefore we would need very smart users - or at least with a good memory - to add product data and then not to forget to add the receipt prices.
A more general solution would be to maintain a local list of "to-be-created-or-edited" products.