Note that we used to have the link to delete images inside the same
<form> tag as the button to update the image. However, using a button
means we're adding a new <form> tag for the action to delete the image.
This isn't valid HTML and, in some browsers, might result in the button
sending the request to the wrong URL.
As explained in commit 5311daadf, to avoid this, we'd need to replace
`button_to` with `button_tag` in the action in order to generate a
button without a form. Then, we could add either a `form` or a
`formaction` attribute to the button.
However, I thik it's easier to move the delete button outside the update
button <form> tag. On the minus side, since the buttons no longer share
a parent, they're harder to style. So we're using a mix of nested flex
layouts with one of the nested elements using a container unit as width.
Since we're at it, we're also improving the styles on small and medium
screens by making sure the "Update" button wraps before the "Delete"
button does (using a container query), by giving enough width to the
column containing this actions on small screens as well (removing
`small-12` and giving it two-thirds of the width on all screen sizes)
and by having a gap between elements.
Note that, at the time of writing, container queries are only supported
by about 91%-93% of the browsers, meaning that some administrators will
see all from controls displayed vertically, one on top of the other, on
all screen sizes. We think this is acceptable, and the page remains
fully functional in this case.
