add "Replying as {channel}" to reply input label for comments

ui/component/commentCreate/view.jsx

@@ -99,7 +99,7 @@ export function CommentCreate(props: Props) {
         disabled={channel === CHANNEL_NEW}
         type="textarea"
         name="content_description"
-        label={__('Comment')}
+        label={isReply ? __('Replying as %reply_channel%', { reply_channel: channel }) : __('Comment')}
         onFocus={onTextareaFocus}
         placeholder={__('Say something about this...')}
         value={commentValue}

ui/scss/init/_gui.scss

@@ -119,6 +119,11 @@ a {
   -webkit-user-drag: none;
 }
 
+img {
+  // Hide alt text when an image fails to load
+  text-indent: -9999px;
+}
+
 .columns {
   display: flex;
   justify-content: space-between;