PLT-3177 - Fixing ordering for custom themes (#3226)

Fix for bot tag and webhook attachments

Adding theme styling for webhooks

Removing embed styling

Improving margins on compcat view for line breaks

webapp/components/post_view/components/post_header.jsx

@@ -38,7 +38,7 @@ export default class PostHeader extends React.Component {
                 );
             }
 
-            botIndicator = <li className='col col__name bot-indicator'>{Constants.BOT_NAME}</li>;
+            botIndicator = <li className='bot-indicator'>{Constants.BOT_NAME}</li>;
         } else if (PostUtils.isSystemMessage(post)) {
             userProfile = (
                 <UserProfile