Fix some UI problems (dropdown/container) (#30849)

Follow #30345
Follow #30547

`ellipsis` / `white-space` shouldn't be put on the general dropdown components.

web_src/js/features/repo-issue.js

@@ -124,8 +124,8 @@ export function initRepoIssueSidebarList() {
               return;
             }
             filteredResponse.results.push({
-              name: `#${issue.number} ${htmlEscape(issue.title)
-              }<div class="text small gt-word-break">${htmlEscape(issue.repository.full_name)}</div>`,
+              name: `<div class="gt-ellipsis">#${issue.number} ${htmlEscape(issue.title)}</div>
+<div class="text small gt-word-break">${htmlEscape(issue.repository.full_name)}</div>`,
               value: issue.id,
             });
           });