Update registerTool function signature for proper typed ToolCalback

[gching]

• Updates registerTool signature to provide the accurate type for the ToolCallback

Motivation and Context

• Currently, even though no inputSchma is provided, given the generic, it will assume the ToolCallback function will always be cb(params, extra) even though it should be cb(extra)
• In these cases, params will be typed as the Record<string, any> even though it should be typed RequestHandlerExtra and extra would be typed as RequestHandlerExtra but actually be undefined
• After the change, we have a properly typed ToolCallback where if inputSchema is undefined, the callback will be cb(extra) and if inputSchema is defined, it will be cb(params, extra)

How Has This Been Tested?

• Local type check

Breaking Changes

• Probably not, just removing typecasts + @ts-ignore

Types of changes

• Bug fix (non-breaking change which fixes an issue)

Checklist

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