feat(server): random assets API (#4184)

* feat(server): get random assets API

* Fix tests

* Use correct validation annotation

* Fix offset use in query

* Update API specs

* Fix typo

* Random assets e2e tests

* Improve e2e tests

mobile/openapi/lib/api/asset_api.dart

@@ -1028,6 +1028,60 @@ class AssetApi {
     return null;
   }
 
+  /// Performs an HTTP 'GET /asset/random' operation and returns the [Response].
+  /// Parameters:
+  ///
+  /// * [num] count:
+  Future<Response> getRandomWithHttpInfo({ num? count, }) async {
+    // ignore: prefer_const_declarations
+    final path = r'/asset/random';
+
+    // ignore: prefer_final_locals
+    Object? postBody;
+
+    final queryParams = <QueryParam>[];
+    final headerParams = <String, String>{};
+    final formParams = <String, String>{};
+
+    if (count != null) {
+      queryParams.addAll(_queryParams('', 'count', count));
+    }
+
+    const contentTypes = <String>[];
+
+
+    return apiClient.invokeAPI(
+      path,
+      'GET',
+      queryParams,
+      postBody,
+      headerParams,
+      formParams,
+      contentTypes.isEmpty ? null : contentTypes.first,
+    );
+  }
+
+  /// Parameters:
+  ///
+  /// * [num] count:
+  Future<List<AssetResponseDto>?> getRandom({ num? count, }) async {
+    final response = await getRandomWithHttpInfo( count: count, );
+    if (response.statusCode >= HttpStatus.badRequest) {
+      throw ApiException(response.statusCode, await _decodeBodyBytes(response));
+    }
+    // When a remote server returns no body with a status of 204, we shall not decode it.
+    // At the time of writing this, `dart:convert` will throw an "Unexpected end of input"
+    // FormatException when trying to decode an empty string.
+    if (response.body.isNotEmpty && response.statusCode != HttpStatus.noContent) {
+      final responseBody = await _decodeBodyBytes(response);
+      return (await apiClient.deserializeAsync(responseBody, 'List<AssetResponseDto>') as List)
+        .cast<AssetResponseDto>()
+        .toList();
+
+    }
+    return null;
+  }
+
   /// Performs an HTTP 'GET /asset/time-buckets' operation and returns the [Response].
   /// Parameters:
   ///