align structure more with underlying chunk layout

src/models/data/data-tracker-timestamp-chunk.ts

@@ -0,0 +1,10 @@
+import { Chunk } from '../chunk';
+
+export interface DataTrackerTimestampChunkData {
+  timestamp: bigint;
+}
+
+export interface DataTrackerTimestampChunk {
+  chunk: Chunk;
+  data: DataTrackerTimestampChunkData;
+}