Add hover background to wiki list page (#27507)

This patch adds a hover background for the wiki row in wiki list page,
which make its behavior more close to repo's file list page.

This patch also make the wiki-git-entry visible on the row is hovered
instead of the cel, so users won't be confused since the 'grid' is not
visible from the web page.

After the patch: (when the wiki named 'Home' is hovered)

![image](https://github.com/go-gitea/gitea/assets/10095765/f6c67c41-ad54-4ce4-a3b1-8c7551396ce0)

web_src/css/repo/wiki.css

@@ -1,9 +1,13 @@
+.repository.wiki .wiki-pages-list tr:hover {
+  background-color: var(--color-hover);
+}
+
 .repository.wiki .wiki-pages-list .wiki-git-entry {
   margin-left: 10px;
   display: none;
 }
 
-.repository.wiki .wiki-pages-list td:hover .wiki-git-entry {
+.repository.wiki .wiki-pages-list tr:hover .wiki-git-entry {
   display: inline-block;
 }