[Planned] Check if theme child is activate to doesn't make parent theme inactive

[Matheus_Bavaresco]

In some cases the theme “Divi” appears to me as an inactive theme. But in fact its child version is active, so the “Divi” which is the parent theme is inactive. But if I delete it, the site breaks, because the “Divi-child” does not run without the “Divi” parent.