Improve Command System: Added Command Pattern and Editor Integration

[bhadrik]

Summary of Changes

• Implemented the Command Pattern for network command execution to improve scalability and maintainability of command handling.
• Exposed all registered commands within the MCP Editor window for easier discovery and debugging.

Developer Notes

To add a new command, simply create a handler class and register the command using the CommandRegistry. This approach enables modular command management and simplifies the process of extending the command system.

Example:

[InitializeOnLoad]
public static class NewCommand
{
    static NewCommand()
    {
        CommandRegistry.RegisterCommand("new_command", HandleCommand);
    }

    public static object HandleCommand(JObject @params)
    {
        // Implement command handling logic here
    }
}

[michaelnugent]

FYI I applied this PR to my fork michaelnugent/unity-mcp@5fcb545

[bhadrik]

I have created agent inside of Unity instead of managing MCP, check it out here.
https://github.com/bhadrik/unity-autopilot