Search: Populate search bar with ChannelId (#3805)

src/invidious/routes/channels.cr

@@ -278,6 +278,7 @@ module Invidious::Routes::Channels
       return error_template(500, ex)
     end
 
+    env.set "search", "channel:#{ucid} "
     return {locale, user, subscriptions, continuation, ucid, channel}
   end
 end

src/invidious/routes/search.cr

@@ -65,7 +65,11 @@ module Invidious::Routes::Search
 
       redirect_url = Invidious::Frontend::Misc.redirect_url(env)
 
-      env.set "search", query.text
+      if query.type == Invidious::Search::Query::Type::Channel
+        env.set "search", "channel:#{query.channel} #{query.text}"
+      else
+        env.set "search", query.text
+      end
       templated "search"
     end
   end