Report MCP error codes with server attribution

[aibrahim-oai]

Why

MCP error-code telemetry special-cased Codex Apps: its reported error codes were retained, while codes from every other MCP server were replaced with unknown. Error reporting should behave consistently for every MCP server. The server name already identifies where an error came from, so telemetry does not need a separate Codex Apps classification.

This follows up on #28976, which introduced MCP error-code telemetry.

What changed

• Add the MCP server name to call, duration, and error metrics.
• Retain bounded, sanitized tool error codes from every MCP server.
• Remove McpErrorCodeSource and the Codex Apps ownership lookup from telemetry collection.
• Use the same metric-tagging path for blocked, rejected, and executed MCP calls.

Test plan

• Verify the complete metric tag set includes the sanitized MCP server name.
• Verify error codes from ordinary MCP servers are retained, bounded, and sanitized.
• Preserve coverage for request failures, tool-result failures, nested auth failures, and span attributes.