User cannot use keyboard shortcuts to copy comment text to clipboard

[cindywu]

Bug
User tried to use cmd+a cmd+c to copy text in comment box.

Steps to reproduce

Hitting cmd+a to copy my comment closed out of the comment box (because I was trying to cmd+a and cmd+c to save it in case it disappeared).

Expected behavior
User should be able to open comment box, focus on specific comment, use keyboard shortcuts cmd+a to highlight comment text, use keyboard shortcut cmd+c to copy highlighted comment text.

[cindywu]

dup of #428