[bug 1077423] Overhaul generic feedback form dev

* switches from 3 cards to 2
* switches from happy/sad images in a png sprite to inline SVG
* switches from brick to a simpler card system
* reduces text to the user and makes it more direct so it's clearer
  what's being asked
* makes private/public information clearer
* make the form keyboard-friendlier
[bug 1077423] Update smoke tests for generic feedback form dev
Merge pull request #377 from willkg/1077423-overhaul-generic

1077423 overhaul generic