feat(mcp): add elicitation request handling

[mattzcarey]

Add support for MCP elicitation requests across the codebase:

• Add elicitation store to sync context with requested/completed/rejected event handlers
• Add ElicitationPrompt component to session UI with priority after permissions and questions
• Register elicitation identifier prefix "eli"
• Implement elicitation request handler in MCP client with form capabilities
• Add /mcp/elicitation routes for list, reply, and reject operations
• Generate SDK types

What does this PR do?

adds elicitation for human in the loop.

How did you verify your code works?

it works locally for me

Closes #8251