Add hyperlink to draft comments banner

Some users were not able to find the closed changes with draft comments
referred to by the banner.

This change adds a "view all" link to the query for all closed changes
with draft comments to provide additional context to the user.

Bug: Issue 9771
Change-Id: I61ebb7e50558b487afb8729ba2a4b8da8cef579b

polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view.html

@@ -68,6 +68,7 @@ limitations under the License.
     <div class$="banner [[_computeBannerClass(_showDraftsBanner)]]">
       <div>
         You have draft comments on closed changes.
+        <a href$="[[_computeDraftsLink(_showDraftsBanner)]]" target="_blank">(view all)</a>
       </div>
       <div>
         <gr-button

polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view.js

@@ -244,5 +244,9 @@
     _closeConfirmDeleteOverlay() {
       this.$.confirmDeleteOverlay.close();
     },
+
+    _computeDraftsLink() {
+      return Gerrit.Nav.getUrlForSearchQuery('has:draft -is:open');
+    },
   });
 })();