Add MCP server management UI in AI Catalog

What does this MR do and why?

Add MCP server management UI in AI Catalog

• Extracted from: Draft: MCP Servers in AI Catalog PoC (!220783 - closed), that MR provides the whole picture
• Demo (Slack): https://gitlab.slack.com/archives/C08T5J1KXKQ/p1769546916417669
• Related issue: Enable custom agents to access external data vi... (#590708 - closed)

This MR adds frontend components for managing Model Context Protocol (MCP) servers in the AI Catalog:

• New MCP server creation, listing, and detail pages
• Form components for MCP server configuration (URL, auth, transport)
• Project-level MCP server view showing which agents use each server
• GraphQL queries and mutations for MCP server operations
• Router and navigation updates to support MCP server pages

The UI supports OAuth and no-auth authentication types with HTTP transport protocol.

The changes are behind ai_catalog_mcp_servers feature flag: [FF] `ai_catalog_mcp_servers` -- Controls wheth... (#587925)

References

Screenshots or screen recordings

Empty list:

New MCP Server form

MCP Servers list

MCP Server Show