[Feature]: Add option to share a user's profile on their Librelinks page

[urdadx]

Description

Add the share button to the top-left of the page as illustrated above. When clicked, the button should reveal a modal with options:

1. Copy the link URL
2. Download via QR code

The Modal should look something like this👇 (you can re-use the share-modal component) :

Make it responsive both on mobile and desktop

Screenshots (if applicable)

No response

Checklist

• Checked existing issues
• Willing to contribute (optional)