HTML: Add rel="noreferrer noopener" to external links (#4667)

Note: Does not add rel="noreferrer noopener" to:
 * links in channel description
 * links in video descriptions
 * links in video comments

Related to issue 4267

src/invidious/frontend/comments_youtube.cr

@@ -149,12 +149,12 @@ module Invidious::Frontend::Comments
 
         if comments["videoId"]?
           html << <<-END_HTML
-            <a href="https://www.youtube.com/watch?v=#{comments["videoId"]}&lc=#{child["commentId"]}" title="#{translate(locale, "YouTube comment permalink")}">[YT]</a>
+            <a rel="noreferrer noopener" href="https://www.youtube.com/watch?v=#{comments["videoId"]}&lc=#{child["commentId"]}" title="#{translate(locale, "YouTube comment permalink")}">[YT]</a>
             |
           END_HTML
         elsif comments["authorId"]?
           html << <<-END_HTML
-            <a href="https://www.youtube.com/channel/#{comments["authorId"]}/community?lb=#{child["commentId"]}" title="#{translate(locale, "YouTube comment permalink")}">[YT]</a>
+            <a rel="noreferrer noopener" href="https://www.youtube.com/channel/#{comments["authorId"]}/community?lb=#{child["commentId"]}" title="#{translate(locale, "YouTube comment permalink")}">[YT]</a>
             |
           END_HTML
         end

src/invidious/helpers/errors.cr

@@ -190,7 +190,7 @@ def error_redirect_helper(env : HTTP::Server::Context)
           <a href="/redirect?referer=#{env.get("current_page")}">#{switch_instance}</a>
         </li>
         <li>
-          <a href="https://youtube.com#{env.request.resource}">#{go_to_youtube}</a>
+          <a rel="noreferrer noopener" href="https://youtube.com#{env.request.resource}">#{go_to_youtube}</a>
         </li>
       </ul>
     END_HTML

src/invidious/views/components/video-context-buttons.ecr

@@ -1,6 +1,6 @@
 <div class="flex-right flexible">
     <div class="icon-buttons">
-        <a title="<%=translate(locale, "videoinfo_watch_on_youTube")%>" href="https://www.youtube.com/watch<%=endpoint_params%>">
+        <a title="<%=translate(locale, "videoinfo_watch_on_youTube")%>" rel="noreferrer noopener" href="https://www.youtube.com/watch<%=endpoint_params%>">
             <i class="icon ion-logo-youtube"></i>
         </a>
         <a title="<%=translate(locale, "Audio mode")%>" href="/watch<%=endpoint_params%>&listen=1">

src/invidious/views/playlist.ecr

@@ -83,7 +83,7 @@
 
         <% if !playlist.is_a? InvidiousPlaylist %>
             <div class="pure-u-2-3">
-                    <a href="https://www.youtube.com/playlist?list=<%= playlist.id %>">
+                    <a rel="noreferrer noopener" href="https://www.youtube.com/playlist?list=<%= playlist.id %>">
                         <%= translate(locale, "View playlist on YouTube") %>
                     </a>
                     <span> | </span>

src/invidious/views/watch.ecr

@@ -123,8 +123,8 @@ we're going to need to do it here in order to allow for translations.
                         link_yt_embed = IV::HttpServer::Utils.add_params_to_url(link_yt_embed, link_yt_param)
                     end
                 -%>
-                <a id="link-yt-watch" data-base-url="<%= link_yt_watch %>" href="<%= link_yt_watch %>"><%= translate(locale, "videoinfo_watch_on_youTube") %></a>
+                <a id="link-yt-watch" rel="noreferrer noopener" data-base-url="<%= link_yt_watch %>" href="<%= link_yt_watch %>"><%= translate(locale, "videoinfo_watch_on_youTube") %></a>
-                (<a id="link-yt-embed" data-base-url="<%= link_yt_embed %>" href="<%= link_yt_embed %>"><%= translate(locale, "videoinfo_youTube_embed_link") %></a>)
+                (<a id="link-yt-embed" rel="noreferrer noopener" data-base-url="<%= link_yt_embed %>" href="<%= link_yt_embed %>"><%= translate(locale, "videoinfo_youTube_embed_link") %></a>)
             </span>
 
             <p id="watch-on-another-invidious-instance">