feat: turn chatflow into MCP server (#5930)

* feat: turn chatflow into MCP server

- Added '@modelcontextprotocol/sdk' version 1.12.0
- Added 'zod' version 3.25.32
- Added migrations for MCP server config
- Added MCP endpoints (Streamable HTTP and SSE)
- Added MCP server configuration tab
- Added unit tests for MCP endpoints and services

* feat: Implement MCP endpoint service with SSE support

- Added a new MCP endpoint service to handle requests for chatflows, including support for SSE (Server-Sent Events) and stateless transport.
- Introduced functions for handling MCP requests, SSE connections, and message routing.
- Implemented error handling for service errors and session management for SSE.
- Created unit tests for the MCP server service, covering configuration CRUD operations and token management.
- Updated the MCP server configuration logic to ensure proper validation and error handling.
- Refactored the UI component to utilize a new API hook for fetching MCP server configuration.

* chore: handle error when get mcp server config

* - Introduced a new chat type 'MCP' in the ChatType enum, including UI filters and backend processing.
- Updated the zod dependency version specification to support both ^3.25.76 and ^4.
- Fix setHasExistingConfig

* fix: update chatflowCallback to enable chatflow building with active state for MCP

* refactor: remove deprecated SSE transport endpoints and related logic

- Removed handleGet and handleSseMessage methods from MCP endpoint controller.
- Updated MCP endpoint routes to eliminate SSE-related routes.
- Refactored service layer to remove SSE session management and related methods.
- Updated tests to remove references to deprecated SSE functionality.
- Adjusted UI component to remove SSE endpoint URL handling.

* chore: update MCP endpoint routes and references to align with new API structure

* chore: remove abortChatMessage when mcp request closed

* optimize mcpserver dialog for dark mode

* feat: implement form input schema generation for agentflow chatflows

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Co-authored-by: Henry <hzj94@hotmail.com>