Rewrite and restyle reaction selector and enable no-sizzle eslint rule (#30453)

Enable `no-sizzle` lint rule, there was only one use in `initCompReactionSelector` and:

- Remove all jQuery except the necessary fomantic dropdown init
- Remove the recursion, instead bind event listeners to common parent container nodes

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Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: Giteabot <teabot@gitea.io>

web_src/css/index.css

@@ -62,6 +62,7 @@
 @import "./repo/linebutton.css";
 @import "./repo/wiki.css";
 @import "./repo/header.css";
+@import "./repo/reactions.css";
 
 @import "./editor/fileeditor.css";
 @import "./editor/combomarkdowneditor.css";