Add a hashtag public link to the trending hashtag page (#17140)

* Add a hashtag public link to the hashtag management page

* Add support for element 'target' to Counter.js.
Remove 'rel' element.

* Update app/javascript/mastodon/components/admin/Counter.js

Co-authored-by: Claire <claire.github-309c@sitedethib.com>

Co-authored-by: Eugen Rochko <eugen@zeonfederated.com>
Co-authored-by: Claire <claire.github-309c@sitedethib.com>