Add New Recovery Method dialog

Adds a New Recovery Method dialog which is shown when key backup fails because
of a version mismatch / version not found error.

The set up button in the dialog currently only marks a device as verified (via a
verification prompt) instead of the eventual restore and cross-sign flow, since
those pieces don't exist yet.

Signed-off-by: J. Ryan Stinnett <jryans@gmail.com>

res/css/_common.scss

@@ -34,7 +34,7 @@ body {
     -webkit-font-smoothing: subpixel-antialiased;
 }
 
-div.error, div.warning {
+.error, .warning {
     color: $warning-color;
 }