FEATURE: my threads page (#24771)

This commit adds a new "My threads" link in sidebar and drawer. This link will open the "/chat/threads" page which contains all threads where the current user is a member. It's ordered by activity (unread and then last message created).

Moreover, the threads list of a channel page is now showing every threads of a channel, and not just the ones where you are a member.

plugins/chat/test/javascripts/components/chat-message-collapser-test.js

@@ -429,7 +429,7 @@ module(
       );
       assert.true(
         queryAll(".chat-message-collapser-link-small")[1].innerHTML.includes(
-          "%3Cscript%3Esomeeviltitle%3C/script%3E"
+          "<script>someeviltitle</script>"
         )
       );
     });