🎨 style(nodeToolbarComponent): update button colors and icons for better visibility and consistency

🐛 fix(nodeToolbarComponent): fix documentation link not working when no documentation is provided
The button colors and icons have been updated to improve visibility and consistency. The delete and copy buttons now have a darker background color when hovered over. The edit button now has a rounded right corner and a lighter background color when there are no nodes present. The documentation button now shows a "Coming Soon" tooltip when no documentation is provided and has a muted color. The documentation link now works correctly even when no documentation is provided.