Rewrite a lot of legacy strange code, remove duplicate code, remove
jquery, and make these filters reusable.
Let's forget the old code, new code affects:
* issue list open/close switch
* issue list filter (label, author, assignee)
* milestone list open/close switch
* milestone issue list filter (label, author, assignee)
* project view (label, assignee)
1. add backend support for filtering "poster" and "assignee"
* due to the limits, there is no frontend support at the moment
2. rewrite TS code without jquery, now there are 14 jQuery files left: