Setup redesign

Merge remote-tracking branch 'origin/pr/14507' into 3.x

* origin/pr/14507: (39 commits)
  Fixed rule for checking upgradable version
  Improved setup workflow - added missed autofocus attributes
  Improved keyboard navigation a bit
  Load list of available languages
  Added styles for language selector
  Added translation for languages
  Fixed missed conflict
  Improved logic of getting languages
  Added styles for new language selector on setup
  Minor design tweaks
  Minor changes styles
  Improved dealing with success/failed messages on pages
  Minor design tweaks
  Changes after review
  Added style for current step
  Remove toggling messages in the finish install screen
  Remove checking old versions ie and some cleanup
  Change styles for setup_body
  Minor change inputs and  labels
  Small changes and add label for option item
  ...

_build/templates/default/sass/_colors-and-vars.scss

@@ -15,11 +15,13 @@ $mediumGray: #999999;
 $darkGray: #515151;
 $darkestGray: #53595F; /* a blueish dark gray */
 $osloGray: #868B8F;
-$doveGray: #686868;
-$alto: #DFDFDF;
-$white: #FFFFFF;
+$doveGray: #686868;  ;
 $alabastersolid: #FAFAFA;
 $tundora: #444444;
+$scorpion: #606060;
+$mineShaft: #343434;
+$alto: #DFDFDF;
+$white: #FFF;
 $black: darken($colorSplash, 42.5%); /* generate the black from the $colorSplash */
 $darkBlack: #000;
 $lighterRed: #FFEEEE;