Add Mail.app Integration for Email Creation

[2b3pro]

This PR introduces Mail.app integration to the AppleScript MCP server, adding the ability to programmatically create new emails. Key changes:

• Adds new mailCategory with initial create_email functionality
• Implements proper URL encoding for subject and body text to handle special characters
• Uses Mail.app's mailto protocol for reliable email creation
• Includes input validation through JSON schema for recipient, subject, and body fields

The implementation uses AppleScript's native URL handling capabilities combined with proper character encoding to ensure reliable email creation across different text inputs.

Note: the mailto command in AppleScript provides a workaround for a strange quirky inclusion of a carriage return in Apple Mail using the make new message method that turns the message into quoted message rather than the main body.