fix mcp.types.Tool is not following python's naming convention snake_case

[azdolinski]

Renamed the inputSchema field to input_schema in the Tool class to align with Python's naming conventions (snake_case). Added an alias inputSchema for backward compatibility.

Motivation and Context

The name inputSchema does not follow Python's naming convention (PEP 8). This change improves code readability and consistency. Fix related: #97

How Has This Been Tested?

Tested locally by running existing tests.

Breaking Changes

• [X] Yes. Users will need to update references to the inputSchema field to input_schema. Adding an alias is intended to ease the migration.

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [X] Breaking change (fix or feature that would cause existing functionality to change)
• [ ] Documentation update

Checklist

• [X] I have read the MCP Documentation
• [X] My code follows the repository's style guidelines
• [X] New and existing tests pass locally
• [X] I have added appropriate error handling
• [X] I have added or updated documentation as needed

Additional context

The addition of the inputSchema alias is intended to provide backward compatibility and facilitate the migration process for users.