[BUU] Remove StimulusReflex from Image Edit

[dacook]

What? Why?

Because I have had quite enough of StimulusReflex.

• Closes #12399

Although I have to admit I'm not entirely impressed by Turbo either. I was hoping to also implement dynamic reloading of the new image in-place (rather than reloading the whole page), but had some limitations:

• Turbo Frame: It would require a bit of a weird setup with a few partials and I think it will be a bit hard for a newcomer to understand (defeating the purpose of using frames I think).
• Turbo Streams: Almost got it, but for some reason the form wasn't submitting for turbo streams.

So I think the next step would be to either try harder with Turbo, or just write a Stimulus Controller to do what we want.

FYI for reviewers, there's already a system spec, and it continues to just work :D

What should we test?

/admin/products with admin_Style_v3 enabled

For each of:

• product with an image.
• product with the default image (ofn logo).
• With any url params like ?page=2 (note that you might have to add these manually, due to https://github.com/openfoodfoundation/openfoodnetwork/issues/11640)

1. Click on the image, view the modal. Close the modal.
2. Click on the image again, upload a new one
3. Image should be updated, with success message. You should land on the right page too.