Option for plugins to set the parent icon for a nested `GameMenuItem`

[mtkennerly]

Feature description

In this screenshot, I'd like "restore save data..." to have an icon, but I can only seem to add it for the individual backups (the nested options on the right):

The individual backups are defined as:

new GameMenuItem
{
    Description = Etc.GetBackupDisplayLine(backup),
    MenuSection = string.Format("{0} | {1}", translator.Ludusavi(), translator.RestoreSelectedGames_Label()),
    Action = async args => { /* ... */ }
}

If I add an extra GameMenuItem for the parent with an icon, then I get one with the icon and one without:

new GameMenuItem
{
    Description = translator.RestoreSelectedGames_Label(),
    MenuSection = translator.Ludusavi(),
    Icon = interactor.GetIcon(Icon.UploadAlt)
}

Screenshots

No response