fix(submit): drop the redundant featured preview type badge

The reference theme renders no type badge in the featured box; the
swiper and dplayer previews are self-explanatory. Remove it from both
preview branches and delete the now-unused CSS rule.

assets/js/front-submit.js

@@ -449,8 +449,7 @@
           '<div class="swiper-button-prev"></div>' +
           '<div class="swiper-button-next"></div>' +
           '<div class="swiper-pagination"></div>' +
-          '</div>' +
-          '<span class="featured-type-badge"><i class="fa fas fa-image"></i></span>';
+          '</div>';
       } else if (t === 'video') {
         html =
           '<div class="new-dplayer dplayer-scale-height" style="--scale-height:50%;" video-url="' +
@@ -459,8 +458,7 @@
           escapeHtml(d.pic || '') +
           '"><div class="graphic" style="padding-bottom:50%;">' +
           '<div class="abs-center text-center"><i class="fa fas fa-play-circle fa-4x muted-3-color opacity5" aria-hidden="true"></i></div>' +
-          '</div></div>' +
-          '<span class="featured-type-badge"><i class="fa fas fa-video"></i></span>';
+          '</div></div>';
       }
       this.destroyFeaturedPlayer(preview);
       preview.innerHTML = html;