Add widget theme settings

Checklist

• I've already searched in existing issues and haven't found a similar feature request.

Which category best fits this feature request?

User Interface

Is your feature request related to a problem? Please describe.

I'm really liking the new widget! There are two things I'd really like to have.

• Widget theming
  • Especially the ability to set a background color(that includes transparent), and a text color. It's jarring to have a dark theme home screen, but have a white background.
• Widget system font. Honestly it'd probably be best to just remove this as a specific widget setting, and have the font match the one in the feed view. I don't know any other android app with a widget that lets you set a custom font different from what the app uses.

Describe the solution you'd like

See above.

Related links

NA

The request concerns the Android widget and its relationship to the feed view, but names no files or tests. Start by locating the widget implementation and existing widget settings, then compare its font and theme behavior with the feed view; done means configurable background and text colors, including transparency, and the widget using the app's feed-view font.