Filter screenshots by environment

[danirabbit]

Problem

Apps can provide multiple screenshots for different desktop environments or using light and dark styles. There is a way now in appstream for developers to declare the environment of a screenshot, but AppCenter just shows all screenshots

Proposal

Filter screenshots to match the current desktop environment and match the dark/light style preference. For example, Harvey should show the light screenshot in light mode and the dark screenshot in dark mode, but not both

Prior Art (Optional)

No response