Add rel="noopener" to target="_blank" links

src/invidious/views/data_control.ecr

@@ -13,7 +13,7 @@
             </div>
 
             <div class="pure-control-group">
-                <label for="import_youtube">Import <a target="_blank"
+                <label for="import_youtube">Import <a rel="noopener" target="_blank"
                         href="https://support.google.com/youtube/answer/6224202?hl=en-GB">YouTube subscriptions</a></label>
                 <input type="file" id="import_youtube" name="import_youtube">
             </div>

src/invidious/views/watch.ecr

@@ -218,7 +218,7 @@ function get_reddit_comments() {
                     {title} \
                 </h3> \
                 <b> \
-                    <a target="_blank" href="https://reddit.com{permalink}">View more comments on Reddit</a> \
+                    <a rel="noopener" target="_blank" href="https://reddit.com{permalink}">View more comments on Reddit</a> \
                 </b> \
             </div> \
             <div>{contentHtml}</div> \