Extends the ExceptionGroup unwrapping fix from mcp_tool_executor to the
base MCP client implementations (AsyncBaseMCPClient, AsyncFastMCPSSEClient,
AsyncFastMCPStreamableHTTPClient). When ToolError exceptions are wrapped
in ExceptionGroup by Python's async TaskGroup, the exception handler now
unwraps single-exception groups before checking class names.
This prevents wrapped ToolError exceptions from being logged to Datadog
as unexpected errors instead of being handled as expected validation failures.
Related to commit 1cbf1b231 which fixed the same issue in mcp_tool_executor.
🐾 Generated with [Letta Code](https://letta.com)
Co-authored-by: Letta <noreply@letta.com>
98fa16899b