feat: highlight selected tags on the tags page

[sshanzel]

Discussed in #1342

^{Originally posted by plplmax August 17, 2024}
It will be nice if you highlight selected tags on the tags page.

"Choose tags to follow" section in "Feed settings" does not show all tags, therefore, does not show all selected tags.
Now we should use search field above "Choose tags to follow" to check if some tag is selected.

There is a hook called useFeedSettings (iirc) - we can cross check which tags are in there followed by the user then highlight those ones in the tags page.