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/js/features/repo-diff.js

@@ -87,7 +87,6 @@ function initRepoDiffConversationForm() {
         el.classList.add('tw-invisible');
       }
       $newConversationHolder.find('.dropdown').dropdown();
-      initCompReactionSelector($newConversationHolder);
     } catch (error) {
       console.error('Error:', error);
       showErrorToast(i18n.network_error);