[Improvment suggestion] Activate Night mode on existing Pack

[ReuK212]

First of all, thanks for all the work to reverse engineer, create and update that awesome tool !

We use a lot the night mode for quiet times and what I'd love to be able to is to update some existing Packs (official or not), to set them as "night mode compatible".

From what I've seen in your code :

• there is a boolean nightModeAvailable = Optional.ofNullable(root.get(nightModeAvailable))
• But it can't be activated for "non-simple" nodes

I'm no Java king, but I'll gladly try to contribute if you give me any pointers ;)