Dashboard Plugin: made list items even out

[lakesare]

___Why not just use justify-content: space-between?
Because making the last row items flock to the left side tends to be a trouble, solutions would be either not very browser-compatible, or would include some Js.

[arturi]

Love it! 💖 Thank you! Been looking for a good solution for quite some time, this nails it, I think.

1. You introduced uppy-size--xl, that’s for inline: true and width: 1000 or something large like that, right?
2. Should we set some max-width so there’s some sensible limit to the width of the files?

[lakesare]

1. For >900pxs, yes.
2. I played with max-width too, but we don't really need it (even on 100% on my mac they look good, and I imagine it's not a common use case to have the uppy dashboard span entire screen anyway), and any max-width will automatically make items not even.

[arturi]

All right, merged!