Share an image as a proof with Smoothie

[monsieurtanuki]

Problem

It's possible to add Smoothie to the list of suggested apps when you're on your phone and you want to share an image.
Could be a proof image, could be a product image.

Proposed solution

There's a package for that: https://pub.dev/packages/receive_sharing_intent

Additional context

The problem is: ok we open the app through an image, but how can we guide the user to the correct action? (e.g. new product ingredient image or new product proof?).
We can even imagine a multi-image sharing, where we send all the shared images as individual proofs of the same location/date/currency.
cc @raphodn @raphael0202

[teolemon]

We've done that on v2 with Barcode images.
Having multiple actions just means a modal asking what should be done with the photo.

• Here's a related issue in the current app: Allow to select some photos from the gallery app and "Share them to Open Food Facts" #4334

[teolemon]

[monsieurtanuki]

Potentially related to #6043.