style: improve design and add logo

- show data icons in thumbnails in data list items
- add app logo
- fix various visibility issues

src/app/modules/data/data.module.ts

@@ -25,6 +25,7 @@ import {ThingTranslateModule} from '../../translation/thing-translate.module';
 import {MenuModule} from '../menu/menu.module';
 import {StorageModule} from '../storage/storage.module';
 import {DataFacetsProvider} from './data-facets.provider';
+import { DataIconPipe } from './data-icon.pipe';
 import {DataRoutingModule} from './data-routing.module';
 import {DataProvider} from './data.provider';
 import {DataDetailContentComponent} from './detail/data-detail-content.component';
@@ -114,6 +115,7 @@ import {VideoListItem} from './types/video/video-list-item.component';
     SkeletonSegment,
     VideoDetailContentComponent,
     VideoListItem,
+    DataIconPipe,
   ],
   entryComponents: [
     DataListComponent,