How to refresh topic title when it was changed in one of plugin's custom controllers

Development
2

There is a new event for this you can use after

https://github.com/discourse/discourse/commit/f8a31d927f35e1302ec4788b8a430667f703f59a

this.appEvents.trigger('header:update-topic', topic);

Also, if you properly use PostRevisor this is handled automatically for you.