[MemoryZ] Sync changes to internal page (pytorch#153166)

Summary:
For MTIA on-demand mode, since we are not using torch Module. The data upload happens in cpp and doesn't support pickle.
Thus, we store as JSON at the end and need the update visualizer to support it

Test Plan: Check Test plan in D74179606

Differential Revision: D74406209

Pull Request resolved: pytorch#153166
Approved by: https://github.com/sraikund16

Author: mzzchy

torch/utils/viz/MemoryViz.js

@@ -1294,6 +1294,19 @@ function create_settings_view(dst, snapshot, device) {
 }
 
 function unpickle(buffer) {
+  try {
+    const decoder = new TextDecoder();
+    const jsonString = decoder.decode(new Uint8Array(buffer));
+    const data = JSON.parse(jsonString);
+
+    return data;
+  } catch (e) {
+    console.log('Failed to decode the data as JSON, fall back to pickle', e);
+  }
+  return unpickleData(buffer);
+}
+
+function unpickleData(buffer) {
   const bytebuffer = new Uint8Array(buffer);
   const decoder = new TextDecoder();