[Feature] Add Support for handle_tool_error and handle_validation_error in load_mcp_tools

[Chaitanya-Keyal]

Fixes: #263

Summary

This PR enhances the load_mcp_tools function to accept two new optional parameters:

• handle_tool_error
• handle_validation_error

These parameters are forwarded to the StructuredTool constructor for each tool, allowing users to customize how errors and validation issues are handled.

Changes Made

• Updated the load_mcp_tools signature to accept handle_tool_error and handle_validation_error.
• Passed these parameters when instantiating each StructuredTool.

Example Usage

tools = load_mcp_tools(
    ...,
    handle_tool_error=custom_tool_error_handler,
    handle_validation_error=custom_validation_handler
)

This change is fully backward-compatible and does not affect existing behavior if the new parameters are not provided.