Filter Card Browser tags based on currently selected notes

### Description:
Currently, the Card Browser displays all tags irrespective of the selected notes. This can make tag navigation cluttered and less relevant when working with a filtered subset of notes.

### Expected Behavior:
When notes are selected in the Card Browser, only the tags associated with those selected notes should be displayed in the tag list/filter section.

Based on discussion from:
[Reddit Discussion](https://www.reddit.com/r/Anki/comments/1t2g8ht/comment/ojnv2li/?utm_source=chatgpt.com)

Suggested to work on by @david-allison.