feat: add mark_as_read method and remove debug print statements across services and views

src/snek/templates/web.html

@@ -184,6 +184,7 @@
         setTimeout(() => {
             updateLayout(doScrollDownBecauseLastMessageIsVisible)
         }, 1000);
+        app.rpc.markAsRead(channelUid);
     });
 
     initInputField(getInputField());