Implement liquidGlass visuals

[LeviiiCraft2]

This PR introduces the liquidGlass feature, which applies slightly transparent backgrounds to widgets for better readability on iOS "Clear" homescreens (iOS 26+). The changes include:

• Settings update: Added liquidGlass toggle in settings and default settings.
• Widget colors: Updated getItemColors and getLessonColors to apply Liquid Glass overlays dynamically depending on light/dark mode.
• Views update: Applied the Liquid Glass visuals to Absences, Exams, Grades, and Breaks views, ensuring high contrast text for readability.
• Fallback & safety: Added try/catch blocks to avoid breaking the widget if color overrides fail.

Changes:

• 2 commit
• 6 files changed
• 97 additions, 23 deletions

This improves the visual appeal and clarity of the widget while keeping disabled/canceled items readable.
UntisWidget-liquid-glass-implementation.js
Fixing:
#10