feat: replace View channel on YouTube and channel's description external links

src/invidious/channels/about.cr

@@ -159,6 +159,9 @@ def get_about_info(ucid, locale) : AboutChannel
     end
   end
 
+  # use comments link_utils to replace external links with the confirmation page
+  description_html = Invidious::Comments.replace_external_links(description_html)
+
   sub_count = 0
 
   if (metadata_rows = initdata.dig?("header", "pageHeaderRenderer", "content", "pageHeaderViewModel", "metadata", "contentMetadataViewModel", "metadataRows").try &.as_a)

src/invidious/views/components/channel_info.ecr

@@ -37,7 +37,10 @@
 <div class="pure-g h-box">
     <div class="pure-u-1-2">
         <div class="pure-u-1 pure-md-1-3">
-            <a href="<%= youtube_url %>"><%= translate(locale, "View channel on YouTube") %></a>
+            <%-
+                confirm_view_yt = "/confirm_leave?link=#{URI.encode_path(youtube_url)}"
+            -%>
+            <a href="<%= confirm_view_yt %>"><%= translate(locale, "View channel on YouTube") %></a>
         </div>
         <div class="pure-u-1 pure-md-1-3">
             <a href="<%= redirect_url %>"><%= translate(locale, "Switch Invidious Instance") %></a>