feat(lock screen): add settings to choose custom color or show background for non lock screen monitor

[Dadangdut33]

Pull Request

Motivation

This is a small changes / PR to add some customizable appearance for non lock screen monitor because currently it only shows black screen.

Type of Change

Mark the relevant option with an "x".

• Bug fix
• New feature
• Breaking change
• Refactoring

Related Issue

• Closes Feature Request: add option to choose which monitor shows the lock screen #1536

Testing

Describe how you tested your changes and mark the relevant items.

• Tested on niri
• Tested on Hyprland
• Tested on sway
• Tested with different bar positions and density settings
• Tested at different interface scaling values
• Tested with multiple monitors (if applicable)

Screenshots / Videos

Checklist

• Code follows project style guidelines
• Self-reviewed my code
• No new warnings or errors
• Documentation or comments updated (if relevant)

Additional Notes

I tested this on a dual monitor setup

[ItsLemmy]

I believe this would be better with NColorChoice and using one of the colorscheme colors instead of a fixed hexcode like that.

[Dadangdut33]

I believe this would be better with NColorChoice and using one of the colorscheme colors instead of a fixed hexcode like that.

i was thinking of having freedom to choose the color but that would also work great and i could change it to that