Tracking project for 2025-03-26 implementation work

[jspahrsummers]

To make it easier to understand how widely the 2025-03-26 protocol revision is supported and where it's been rolled out, we're introducing a tracking project.

@modelcontextprotocol/sdk-maintainers When you get an opportunity, please make sure the project reflects all ongoing and planned work required in each SDK. 🙏