Add hashtag helper bar to Explore tab and refactor ID

- Add `#videoListTags` container to `views/explore.html` to support the hashtag helper bar in the Explore view.
- Rename `#recentVideoTags` to `#videoListTags` in `views/most-recent-videos.html` for consistency across views.
- Update `js/ui/videoListViewController.js` and `js/app.js` to reference the new generic `#videoListTags` ID.
- Update `tests/ui/video-list-view-popular-tags.test.mjs` to reflect the ID change.

This enables the hashtag aggregation and interaction features (filtering, muting, following) on the Explore tab, reusing the existing `VideoListView` logic.

js/ui/videoListViewController.js

@@ -33,7 +33,7 @@ export default class VideoListViewController {
     if (this.isElement(popularTagsContainer)) {
       popularTags = popularTagsContainer;
     } else if (includeTags) {
-      popularTags = this.getElementById("recentVideoTags");
+      popularTags = this.getElementById("videoListTags");
     }
 
     if (typeof view.setPopularTagsContainer === "function") {
@@ -87,7 +87,7 @@ export default class VideoListViewController {
     if (this.isElement(popularTagsContainer)) {
       tagsRoot = popularTagsContainer;
     } else {
-      tagsRoot = this.getElementById("recentVideoTags");
+      tagsRoot = this.getElementById("videoListTags");
     }
     if (typeof view.setPopularTagsContainer === "function") {
       view.setPopularTagsContainer(this.isElement(tagsRoot) ? tagsRoot : null);