Add a batch mode (raw products, receipts)

[raphael0202]

To add prices of raw products (fruits + vegetables), the most effective way seems to take a single picture of a fruit/vegetable shelf.
We could add a batch mode that consists of:

• uploading a single picture
• adding 1+ prices related to this image. We can reuse the same component as in the current price form (category/barcode). We should be able to add several prices in a row, and to update/delete items.
• adding the location/date.
• Submit and send the prices, with a single proof.

This new page can be reused for "receipt mode", the only difference is that the proof type is different.