Comment 1 for bug 2019032

Branch with numerous fixes: https://git.evergreen-ils.org/?p=working/Evergreen.git;a=shortlog;h=refs/heads/user/sleary/lp2019032-lineitem-list-keyboard-support

* <a click()> is now <button type="button">
* All <button>s have a type, to avoid accidentally submitting forms using Spacebar/Enter
* Items in dropdown lists have ngbDropdownItem directive for
keyboard up/down arrow support
* Icons are now aria-hidden (except "close," which is fine as-is)
and their parent elements have ARIA labels where necessary
* Text inputs have labels instead of placeholders