Pull Request Description for dash_navigate Skin Parameter Feature

Title

Add skin parameter to dash_navigate function for dynamic theme switching

Description

This PR adds a new optional skin parameter to the dash_navigate function, allowing users to change dashboard skins/themes during navigation.

What this PR accomplishes:

• Extends the dash_navigate function to accept and process a skin parameter
• Maintains backward compatibility with existing code (parameter is optional)
• Tiny refactor on the update_dash function for better handling of the query params
• I've tried to avoid any new features from JS as I think this project tries to keep compatibility with older browsers (my own case - IPad 3)

Use case:

• Implementing power-saving modes for dashboards (switching to a dark theme when a room is vacant)

Example usage:

# Switch to a dashboard with a specific skin
self.dash_navigate("main_dashboard", skin="dark")

# Standard usage without skin parameter still works
self.dash_navigate("settings_dashboard")

Testing:

I've tested this functionality and verified that the skin parameter correctly applies the specified theme during navigation while preserving all existing functionality.

Closes #2345