feat: enforce MCP request ID validation requirements

[tzolov]

Add MCP-specific ID validation for JSONRPCRequest to enforce protocol compliance.

Alternative implementation of #401

Motivation and Context

The MCP (Model Context Protocol) specification has stricter requirements for request IDs compared to standard JSON-RPC.
Specifically, MCP requires that:

1. Requests MUST include a string or integer ID
2. The ID MUST NOT be null

This change ensures that JSONRPCRequest objects comply with MCP protocol requirements by adding constructor validation that throws an IllegalArgumentException when these requirements are violated.

How Has This Been Tested?

• Added unit tests in JSONRPCRequestMcpValidationTest to verify validation behavior
• Tested scenarios include:
  • Valid string IDs (should pass)
  • Valid integer/long IDs (should pass)
  • Null IDs (should throw IllegalArgumentException)
  • Invalid ID types like boolean or objects (should throw IllegalArgumentException)
• All existing tests continue to pass, ensuring backward compatibility for valid use cases

Breaking Changes

Yes, this is a breaking change. Users who were previously creating JSONRPCRequest objects with:

• Null IDs
• Non-string/non-integer ID types (e.g., boolean, objects)

Will now receive an IllegalArgumentException at construction time. Users need to ensure their request IDs are either strings or integers and are not null.

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