use monet theme for widgets

[veganomy]

Please check before submitting an issue

• I am using the latest version of App Manager
• I have searched the issues and haven't found anything relevant
• I have read the docs

Describe a description of the new feature

Currently the listed useful widgets have static background and foregrounds. This separates App Manager's widgets out from other widgets which do follow color schemes of Android.

Describe the solution you'd like

Use the Android's built-in Material Design colors on widgets for consistent UI.

Describe alternatives you've considered

No response

Additional context

No response