Improve missing cache handling

src/frontend/app/ui/albums/album/album.component.html

@@ -16,7 +16,7 @@
 
   <!--Info box -->
   <div class="info rounded-bottom">
-    {{album.name}} ({{album.cache.itemCount}})
+    {{album.name}} ({{album.cache?.itemCount}})
     <ng-icon *ngIf="CanUpdate && !album.locked"
              (click)="deleteAlbum($event)"
              class="info-button delete float-end"

src/frontend/app/ui/albums/album/album.component.ts

@@ -62,7 +62,7 @@ export class AlbumComponent implements OnInit, OnDestroy {
   ngOnInit(): void {
     if (this.album?.cache?.cover) {
       this.thumbnail = this.thumbnailService.getThumbnail(
-          new Media(this.album.cache.cover, this.size, this.size)
+          new Media(this.album.cache?.cover, this.size, this.size)
       );
     }
   }

src/frontend/app/ui/gallery/navigator/sorting.service.ts

@@ -263,7 +263,7 @@ export class GallerySortingService {
                                 Config.Gallery.enableDirectorySortingByDate === true
                             ) {
                               c.directories.sort(
-                                  (a, b) => (a.cache.oldestMedia || a.lastModified) - (b.cache.oldestMedia || b.lastModified)
+                                  (a, b) => (a.cache?.oldestMedia || a.lastModified) - (b.cache?.oldestMedia || b.lastModified)
                               );
                               break;
                             }