Fixes a few bugs with tags (filtering, media overlay)

__Following bugs fixed:__

* #679 show tags and show description in edit media
* rerender preview when new window is closed (no issue found)
* filtering tags in media edit overlay (part of issue #680)
* filtering tags in tag list (no issue found)

__Tasks:__

- [ ] gather feedback for my changes
- [ ] added changelog line


__Informations:__

| Q             | A
| ------------- | ---
| Tests pass?   | yes
| Fixed tickets | fixes #679 
| BC Breaks     | none
| Doc           | none