containers list: Missing right side of row when downloading

[garrett]

When downloading images to create a container, the row doesn't extend fully. You can easily see this by noticing the divider line doesn't continue to the edge:

This could be solved either with a colspan of 2 on the last row or by having an actions cell too, even if it's empty.

If we can cancel downloading, it'd make sense to have an actions menu anyway. (If we don't, it'd be fine if it's blank.)