Support the addition of maskable icons

Problem/Motivation

This is a follow-up issue to 📌 Logo is being cropped by Android on Home Screen Fixed .

Some operating systems, such as Android, adapt icons to different sizes and shapes. For example, on Android 12, different manufacturers or settings can change the shape of icons from circles to squares to rounded-corner squares. To support these kinds of adaptive icons, a "maskable icon" can be provided.

These "maskable icons" are square images file that have their main icon contained within a circle centered in the icon with a radius of 40 percent of the width of the icon. (For further information on "maskable icons", visit https://web.dev/learn/pwa/web-app-manifest/#maskable-icons)

Steps to reproduce

Proposed resolution

Provide a second image upload field for maskable icons with a size of 512x512, with a description containing a short explanation on maskable icons and a link to the maskable app.

Remaining tasks

User interface changes

API changes

Data model changes