chore: Suggest prompts in llm demo apps

[msluszniak]

Description

This change add suggestions in llm apps to make it easier for testing. Also changes color in hamburger in llm navigation.

Introduces a breaking change?

• Yes
• No

Type of change

• Bug fix (change which fixes an issue)
• New feature (change which adds functionality)
• Documentation update (improves or adds clarity to existing documentation)
• Other (chores, tests, code style improvements etc.)

Tested on

• iOS
• Android

Testing instructions

• Test if suggestions appear correctly in llm apps
• Check that hamburger icons are now visible in llm demo apps.

Screenshots

Related issues

Closes #957

Checklist

• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have updated the documentation accordingly
• My changes generate no new warnings

Additional notes