A implementation for the legacy PocketMine chunk format, and built in methods to convert it to the latest mcworld format.

I speedran this in a day so I could convert the old Origins Survival Games map to the latest world format for use in Oldboat, a recreation of old Lifeboat, but someone else might find this useful.

This one was a bit tricky, because of the way block entities, also known as tiles, are stored in PMF. There's a tiles.yml file that contains tile data, however the formatting is different to modern tile data, so we must implement tile support one by one.

I've implemented support only for signs right now, but I might implement other tiles if found useful.