The modal was broken in two ways:
- On small screens, the input box was partially hanging outside the
modal. Fixed with flexbox and increased modal width.
- The clipboard copy was not working because the modal had both
`data-clipboard-text` and `data-clipboard-target`, while we only support
one of those. Made a small tweak in clipboard as well so that it will
still fall back to target if text is empty.
(cherry picked from commit 94512ee0628dc0d2b697441a4355ace54b6515cd)
