Add iOS 18 icon variants

[defagos]

Description

This PR adds iOS 18 icon variants (for dark / tinted appearance).

Changes made

Self-explanatory.

Checklist

• [x] APIs have been properly documented (if relevant).
• [x] The documentation has been updated (if relevant).
• [x] New unit tests have been written (if relevant).
• [x] The demo has been updated (if relevant).