Add request display mode functionality to AppRenderer and McpClientApp

[gabe4coding]

Introduce functionality for requesting and handling display mode changes in the AppRenderer and McpClientApp components.

Motivation and Context

This change allows the guest UI to request different display modes (inline, fullscreen, pip, carousel) from the host, enhancing user experience and flexibility in UI presentation.
This feature is part of OpenAI Apps SDK.

How Has This Been Tested?

Tested in a development environment by simulating display mode requests and verifying the responses and state updates in the UI.

Breaking Changes

No breaking changes are introduced.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Checklist

• I have read the MCP Documentation
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have added or updated documentation as needed

Additional context

The implementation includes a new request handler in the AppBridge for display mode changes and updates to the UI components to reflect the current display mode. Documentation for the new JSON-RPC method has also been added.