Add the option to keep or remove data to uninstall dialog

[danirabbit]

Problem

The uninstall confirmation dialog still says it "may" delete data from when we had mixed deb and flatpak. But now we can know whether or not it will uninstall data and offer a choice about it

Proposal

Add an option to choose whether I want to keep app data or not

Prior Art (Optional)

iOS has a concept of "Delete" vs "Offload" which is interesting:

GNOME Software does this with radio buttons in the dialog which is quite nice:

[danirabbit]

I like how the explanation text in the iOS design makes a mention of "if the app is still available in the app store" for offload and "this can't be undone" for delete