Override toString() in Info classes to encode them back to JSON

Calling `toString()` on an Info object should return the full JSON representation of the object, including any changes made locally.

This feature makes it easier for applications to cache and store data returned from the API.

The issue refers to the SDK's Info classes and their toString() methods, but names no files or tests. Start by locating the Info classes and existing JSON serialization entry points; done means toString() returns each object's complete JSON representation, including locally changed values, and the behavior is covered by tests.

Written by the indexing model from the issue text.