Add ServerSSESession as a receiver for mcp {} dsl

[nerzhulart]

Motivation and Context

It allows access to an initial HTTP request and its headers to gather additional information from an MCP client

How Has This Been Tested?

Yes

Breaking Changes

Source compatible

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

[devcrocod]

lgtm

Thank you for the contribution
I'll close my pr as a duplicate #180

Could you please update api by calling apiDump?