Add a new exposed 'unpacking' phase to the build and make sure that the unzip/untar/etc always occurs under a try-except

static/js/app.js

@@ -4736,6 +4736,9 @@ quayApp.directive('buildMessage', function () {
           case 'waiting':
             return 'Waiting for available build worker';
 
+          case 'unpacking':
+            return 'Unpacking build package';
+
           case 'pulling':
             return 'Pulling base image';
           
@@ -4791,6 +4794,7 @@ quayApp.directive('buildProgress', function () {
           case 'starting':
           case 'waiting':
           case 'cannot_load':
+          case 'unpacking':
             return 0;
             break;
         }